Oxime ethers as IIb/IIa antagonists

ABSTRACT

This invention relates generally to oxime ethers which are useful as antagonists of the platelet glycoprotein IIb/IIIa fibrinogen receptor complex, to pharmaceutical compositions containing such compounds, processes for preparing such compounds, and to methods of using these compounds for the inhibition of platelet aggregation, as thrombolytics, and/or for the treatment of thromboembolic disorders.

FIELD OF THE INVENTION

The present invention relates generally to oxime ethers which are useful as antagonists of the platelet glycoprotein IIb/IIIa fibrinogen receptor complex, to pharmaceutical compositions containing such compounds, processes for preparing such compounds, and to methods of using these compounds for the inhibition of platelet aggregation, as thrombolytics, and/or for the treatment of thromboembolic disorders.

BACKGROUND OF THE INVENTION

Hemostasis is the normal physiological process in which bleeding from an injured blood vessel is arrested. It is a dynamic and complex process in which platelets play a key role. Within seconds of vessel injury, resting platelets become activated and are bound to the exposed matrix of the injured area by a phenomenon called platelet adhesion. Activated platelets also bind to each other in a process called platelet aggregation to form a platelet plug. The platelet plug can stop bleeding quickly, but it must be reinforced by fibrin for long-term effectiveness, until the vessel injury can be permanently repaired.

Thrombosis may be regarded as the pathological condition wherein improper activity of the hemostatic mechanism results in intravascular thrombus formation. Activation of platelets and the resulting platelet aggregation and platelet factor secretion has been associated with a variety of pathophysiological conditions including cardiovascular and cerebrovascular thromboembolic disorders, for example, the thromboembolic disorders associated with unstable angina, myocardial infarction, transient ischemic attack, stroke, atherosclerosis and diabetes. The contribution of platelets to these disease processes stems from their ability to form aggregates, or platelet thrombi, especially in the arterial wall following injury.

Platelets are activated by a wide variety of agonists resulting in platelet shape change, secretion of granular contents and aggregation. Aggregation of platelets serves to further focus clot formation by concentrating activated clotting factors at the site of injury. Several endogenous agonists including adenosine diphosphate (ADP), serotonin, arachidonic acid, thrombin, and collagen, have been identified. Because of the involvement of several endogenous agonists in activating platelet function and aggregation, an inhibitor which acts against all agonists would represent a more efficacious antiplatelet agent than currently available antiplatelet drugs, which are agonist-specific.

Current antiplatelet drugs are effective against only one type of agonist; these include aspirin, which acts against arachidonic acid; ticlopidine, which acts against ADP; thromboxane A₂ synthetase inhibitors or receptor antagonists, which act against thromboxane A₂; and hirudin, which acts against thrombin.

Recently, a common pathway for all known agonists has been identified, namely platelet glycoprotein IIb/IIIa complex (GPIIb/IIIa), which is the membrane protein mediating platelet aggregation. A recent review of GPIIb/IIIa is provided by Phillips et al. Cell (1991) 65: 359-362. The development of a GPIIb/IIIa antagonist represents a promising new approach for antiplatelet therapy.

GPIIb/IIIa on unstimulated platelets does not bind soluble proteins, but GPIIb/IIIa on activated platelets is known to bind four soluble adhesive proteins, namely fibrinogen, von Willebrand factor, fibronectin, and vitronectin. The binding of fibrinogen and von Willebrand factor to GPIIb/IIIa causes platelets to aggregate. The binding of fibrinogen is mediated in part by the Arg-Gly-Asp (RGD) recognition sequence which is common to the adhesive proteins that bind GPIIb/IIIa.

Several RGD-peptidomimetic compounds have been reported which block fibrinogen binding and prevent the formation of platelet thrombi.

European Patent Application Publication Number 478363 relates to compounds having the general formula:

European Patent Application Publication Number 478328 relates to compounds having the general formula:

European Patent Application Publication Number 525629 (corresponds to Canadian Patent Application Publication Number 2,074,685) discloses compounds having the general formula:

PCT Patent Application 9307867 relates to compounds having the general formula:

European Patent Application Publication Number 512831 relates to compounds having the general formula:

Copending commonly assigned U.S. patent application (U.S. Ser. No. 08/337,920, filed Nov. 10, 1994, Wityak et al.; published as WO95/13155, Jun. 1, 1995) discloses compounds having the general formula:

which are useful as IIB/IIIA antagonists.

Copending commonly assigned U.S. patent application (U.S. Ser. No. 08/455,768, filed May 31, 1995, Voss et al.) discloses compounds having the general formula:

which are useful as a_(v)b₃ antagonists.

None of the above references teaches or suggests the compounds of the present invention which are described in detail below.

SUMMARY OF THE INVENTION

One aspect of this invention provides novel compounds of Formula I (described below) which are useful as antagonists of the platelet glycoprotein IIb/IIIa complex. The compounds of the present invention inhibit the binding of fibrinogen to platelet glycoprotein IIb/IIIa complex and inhibit the aggregation of platelets. The present invention also includes pharmaceutical compositions containing such compounds of Formula I, and methods of using such compounds of Formula I, and methods of using such compounds for the inhibition of platelet aggregation, as thrombolytics, and/or for the treatment of thromboembolic disorders.

The present invention also includes methods of treating cardiovascular disease, thrombosis or harmful platelet aggregation, reocclusion following thrombolysis, reperfusion injury, or restenosis by administering a compound of Formula I alone or in combination with one or more additional therapeutic agents selected from: anti-coagulants such as warfarin or heparin; anti-platelet agents such as aspirin, piroxicam or ticlopidine; thrombin inhibitors such as boroarginine derivatives, hirudin or argatroban; or thrombolytic agents such as tissue plasminogen activator, anistreplase, urokinase or streptokinase; or combinations thereof.

Also included in the present invention are pharmaceutical kits comprising one or more containers containing pharmaceutical dosage units comprising a compound of Formula I, for the treatment of cell adhesion related disorders, including but not limited to thromboembolic disorders.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to novel compounds of Formula I

and pharmaceutically acceptable salt or prodrug forms thereof, wherein:

B is selected from

R²(R^(2a))N—,

R²HN(R^(2a)N═)C—

R²HN(R^(2a)N═)CNH—

Z¹ and Z² are independently selected from

a single bond,

C₁-C₆ alkylene, optionally substituted by R^(2b),

C₂-C₆ alkenylene, optionally substituted by R^(2b),

C₂-C₆ alkynylene, optionally substituted by R^(2b);

wherein any carbon atom in each alkylene, alkenylene or alkynylene chain may optionally be replaced with O, S(O)₀₋₂ or NR⁷, with the proviso that O, S(O)₀₋₂ or NR⁷ when present are adjacent to saturated or aromatic carbon atoms;

V is selected from

a single bond,

1,4-phenylene;

wherein 1-2 carbon atoms in the phenylene may be optionally replaced with N and wherein said phenylene or azaphenylene group is optionally substituted with 1-2 R⁵ substituents; provided that

B, Z¹, Z² and V are chosen such that the oxime carbon in Formula I is not directly connected to an

oxygen, sulfur or nitrogen atom of B, Z¹ or Z²;

L is a C₁-C₄ alkylene chain, C₃-C₄ alkenylene chain or

C₃-C₄ alkynylene chain optionally substituted with

C₁-C₄ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

aryl,

arylmethyl,

heteroaryl,

heteroarylmethyl,

R¹ is selected from

H,

C₁-C₆ alkyl, substituted with 0-2 R⁶,

C₃-C₇ cycloalkyl, substituted with 0-2 R⁶,

aryl, wherein aryl is as defined above;

R² is selected from

H,

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

arylmethyl;

R^(2a) is selected from

H,

OH,

C₁-C₆ alkylcarbonyl,

arylcarbonyl,

C₁-C₆ alkyloxycarbonyl,

C₃-C₇ cycloalkyloxycarbonyl,

aryloxycarbonyl,

aryl(C₁-C₄ alkyl)oxycarbonyl,

C₁-C₆ alkylcarbonyloxy(C₁-C₄ alkyl)oxycarbonyl,

arylcarbonyloxy(C₁-C₄ alkyl)oxycarbonyl,

C₃-C₈ cycloalkylcarbonyloxy(C₁-C₄ alkyl)

oxycarbonyl;

R^(2b) is selected from

H,

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

R³ is selected from

H,

C₁-C₈ alkyl, substituted with 0-2 R⁶,

C₂-C₈ alkenyl, substituted with 0-2 R⁶,

C₂-C₈ alkynyl, substituted with 0-2 R⁶,

C₃-C₇ cycloalkyl, substituted with 0-2 R⁶,

aryl,

heteroaryl,

CONR⁷R⁸;

R⁴ is selected from

H,

C₁-C₆ alkyl,

aryl,

arylmethyl,

heteroaryl,

heteroarylmethyl,

OR¹⁴,

NR⁷R⁸,

NR¹¹R¹⁵;

R⁵ is selected from

H,

halo,

CN,

C₁-C₄ alkyl,

C₁-C₄ haloalkyl,

C₁-C₄ alkyloxy,

C₁-C₄ haloalkyloxy

NR⁷R⁸;

R⁶ is selected from

H,

C₁-C₆ alkyl,

C₂-C₄ alkenyl,

C₃-C₇ cycloalkyl,

C₁-C₄ perfluoroalkyl,

C₁-C₆ alkyloxy,

C₁-C₆ alkylcarbonyl,

aryl,

heteroaryl,

CONR⁷R⁸

OR¹⁴

NR⁹R¹⁰,

NR¹¹COR¹²,

NR¹¹CO₂R¹³

NR¹¹CONR⁷R⁸,

NR¹¹SO₂R¹²,

SO₂R¹²,

SO₂NR⁷R⁸, halo;

R⁷ and R⁸ are independently selected from

H,

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

aryl,

aryl(C₁-C₄ alkyl), or, in a NR⁷R⁸ group, R⁷ and R⁸ can be taken together to form a piperidine, morpholine or thiomorpholine ring, or a piperazine ring in which N-4 is optionally substituted with C₁-C₄ alkyl;

R⁹ and R¹⁰ are independently selected from

H,

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

aryl,

aryl(C₁-C₄ alkyl), or, in a NR⁹R¹⁰ group, R⁹ and R¹⁰ can be taken together to form a piperidine, morpholine or thiomorpholine ring, or a piperazine ring in which N-4 is optionally substituted with C₁-C₄ alkyl;

R¹¹ is selected from

H,

C₁-C₄ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

arylmethyl;

R¹² is selected from

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

aryl,

aryl(C₁-C₄ alkyl),

heteroaryl;

heteroaryl(C₁-C₄ alkyl);

R¹³ is selected from

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

C₁-C₆ haloalkyl,

aryl(C₁-C₄ alkyl),

heteroaryl(C₁-C₄ alkyl);

R¹⁴ is selected from

H,

C₁-C₆ alkyl,

C₁-C₆ haloalkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

CONR⁷R⁸,

aryl,

aryl(C₁-C₄ alkyl);

R¹⁵ is selected from

COR¹⁶,

CO₂R¹⁷,

CONR¹⁸R¹⁹,

SO₂R²⁰,

SO₂NR¹⁸R¹⁹;

R¹⁶ is selected from

H,

C₁-C₈ alkyl, substituted with 0-2 R⁶,

C₂-C₈ alkenyl, substituted with 0-2 R⁶,

C₂-C₈ alkynyl, substituted with 0-2 R⁶,

C₃-C₇ cycloalkyl, substituted with 0-2 R⁶,

aryl,

aryl(C₁-C₄ alkyl),

heteroaryl,

heteroaryl(C₁-C₄ alkyl);

R¹⁷ is selected from

C₁-C₈ alkyl, substituted with 0-2 R⁶,

C₂-C₈ alkenyl, substituted with 0-2 R⁶,

C₂-C₈ alkynyl, substituted with 0-2 R⁶,

C₃-C₇ cycloalkyl, substituted with 0-2 R⁶,

aryl(C₁-C₄ alkyl),

heteroaryl(C₁-C₄ alkyl);

R¹⁸ and R¹⁹ are independently selected from

H,

C₁-C₈ alkyl, substituted with 0-2 R⁶,

C₂-C₈ alkenyl, substituted with 0-2 R⁶,

C₂-C₈ alkynyl, substituted with 0-2 R⁶,

C₃-C₇ cycloalkyl, substituted with 0-2 R⁶,

aryl,

aryl(C₁-C₄ alkyl),

heteroaryl,

heteroaryl(C₁-C₄ alkyl); or, R¹⁸ and R¹⁹ can be taken together to form a piperidine, morpholine or thiomorpholine ring, or a piperazine ring in which N-4 is optionally substituted with C₁-C₄ alkyl;

R²⁰ is selected from

C₁-C₈ alkyl, substituted with 0-2 R⁶,

C₂-C₈ alkenyl, substituted with 0-2 R⁶,

C₂-C₈ alkynyl, substituted with 0-2 R⁶,

C₃-C₇ cycloalkyl, substituted with 0-2 R⁶,

aryl,

heteroaryl,

aryl(C₁-C₄ alkyl),

heteroaryl(C₁-C₄ alkyl);

R²¹ and R²² are selected from

C₁-C₄ alkyl,

arylmethyl, or, R²¹ and R²² can be taken together to form a pyrrolidine, piperidine, morpholine or thiomorpholine ring, or a piperazine ring in which N-4 is optionally substituted with C₁-C₄ alkyl;

R²³ is selected from

C₁-C₄ alkyl,

arylmethyl;

R²⁴ is phenyl or naphthyl optionally substituted with 1-3 substituents selected from C₁-C₆ alkyl, C₁-C₆ alkyloxy, halo, CN, C₁-C₄ haloalkyl, C₁-C₄ haloalkoxy, NO₂, NH₂, C₁-C₆ alkylamino, C₂-C₁₀ dialkylamino, C₁-C₆ alkylcarbonylamino, C₁-C₆ alkylcarbonyl, C₁-C₆ alkyloxycarbonyl, C₁-C₆ alkylthio, C₁-C₆ alkylsulfinyl, C₁-C₆ alkylsulfonyl, C₁-C₆ alkylsulfonylamino, carboxy, aminocarbonyl, C₁-C₆ alkylaminocarbonyl, C₂-C₁₀ dialkylaminocarbonyl or methylenedioxy;

R²⁵ is pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, pyrrolyl, pyrazolyl, imidazolyl, triazolyl, tetrazolyl, furanyl, oxazolyl, isoxazolyl, thienyl, thiazolyl, oxadiazolyl, thiadiazolyl, quinolinyl, isoquinolinyl, benzofuranyl, indolyl, indazolyl, benzimidazolyl or benzothiophenyl, optionally substituted with 1-3 groups selected from C₁-C₆ alkyl, C₁-C₆ alkyloxy, CN, NO₂, halo, C₁-C₄ haloalkyl, C₁-C₆ alkylthio, C₁-C₆ alkylsulfinyl, C₁-C₆ alkylsulfonyl, NH₂, C₁-C₆ alkylcarbonylamino, C₁-C₆ alkylamino or C₂-C₁₀ dialkylamino;

Y is selected from

OH,

C₁-C₁₀ alkyloxy,

C₃-C₇ cycloalkyloxy,

C₄-C₈ cycloalkyloxy,

aryloxy,

arylmethyloxy,

C₁-C₆ alkylcarbonyloxy(C₁-C₄ alkyl)oxy,

C₁-C₆ alkyloxycarbonyloxy(C₁-C₄ alkyl)oxy,

C₃-C₇ cycloalkylcarbonyloxy(C₁-C₄ alkyl)oxy,

C₃-C₇ cycloalkyloxycarbonyloxy(C₁-C₄)oxy,

aryloxycarbonyloxy(C₁-C₄ alkyl)oxy,

arylcarbonyloxy (C₁-C₄ alkyl)oxy,

(C₁-C₄ alkyloxy(C₁-C₆)alkyl)carbonyloxy(C₁-C₄ alkyl)oxy,

(5-(C₁-C₆ alkyl)-1,3-dioxa-cyclopenten-2-one-4-yl)methyloxy,

(5-aryl-1,3-dioxa-cyclopenten-2-one-4-yl)methyloxy,

(R²¹)(R²²)N(C₁-C₆ alkyl)oxy-,

(R²¹)(R²²)(R²³)N⁺(C₁-C₆ alkyl)oxy-(X⁻), where X⁻

is a pharmaceutically acceptable anionic group such as halide, sulfate, organosulfonate or organocarboxylate;

wherein aryl is a phenyl or naphthyl group optionally substituted with 1-3 substituents selected from C₁-C₆ alkyl, C₁-C₆ alkyloxy, halo, CN, C₁-C₄ haloalkyl, C₁-C₄ haloalkoxy, NO₂, NH₂, C₁-C₆ alkylamino, C₂-C₁₀ dialkylamino, C₁-C₆ alkylcarbonylamino, C₁-C₆ alkylcarbonyl, C₁-C₆alkyloxycarbonyl, C₁-C₆ alkylthio, C₁-C₆ alkylsulfinyl, C₁-C₆ alkylsulfonyl, ₁-C₆ alkylsulfonylamino, carboxy, aminocarbonyl, C₁-C₆ alkylaminocarbonyl, C₂-C₁₀ dialkylaminocarbonyl, methylenedioxy and one substituent selected from R²⁴CO, R²⁴O, R²⁴NH, R²⁴S, R²⁴SO, R²⁴SO₂, R²⁴NHCO, R²⁴CONH, R²⁴NHSO₂, R²⁴SO₂NH or phenyl optionally substituted with 1-3 substituents chosen from C₁-C₆ alkyl, C₁-C₆ alkyloxy, halo or C₁-C₄ haloalkyl, except that in the case for R²⁰ aryl can be as defined above but where the three substituents on the phenyl and naphthyl groups may in addition include one substituent selected from R²⁵, R²⁵CO, R²⁵O, R²⁵NH, R²⁵S, R²⁵SO, R²⁵SO₂, R²⁵NHCO, R²⁵CONH, R²⁵NHSO₂ or R²⁵SO₂NH;

and wherein heteroaryl is pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, pyrrolyl, pyrazolyl, imidazolyl, triazolyl, tetrazolyl, furanyl, oxazolyl, isoxazolyl, thienyl, thiazolyl, oxadiazolyl, thiadiazolyl, quinolinyl, isoquinolinyl, benzofuranyl, indolyl, indazolyl, benzimidazolyl or benzothiophenyl, optionally substituted with 1-3 groups selected from C₁-C₆ alkyl, C₁-C₆ alkyloxy, CN, NO₂, halo, C₁-C₄ haloalkyl, C₁-C₆ alkylthio, C₁-C₆ alkylsulfinyl, C₁-C₆ alkylsulfonyl, NH₂, C₁-C₆ alkylcarbonylamino, C₁-C₆ alkylamino, C₂-C₁₀ dialkylamino or one substituent selected from phenyl optionally substituted with 1-3 substituents chosen from C₁-C₆ alkyl, C₁-C₆ alkyloxy, halo or C₁-C₄ haloalkyl, except that in the case for R²⁰ heteroaryl can be defined above but where the three substituents on the heteroaryl ring may in addition include one substituent selected from R²⁴CO, R²⁴O, R²⁴NH, R²⁴S, R²⁴SO, R²⁴SO₂, R²⁴NHCO, R²⁴CONH, R²⁴NHSO₂, R²⁴SO₂NH, R²⁵, R²⁵CO, R²⁵O, R²⁵NH, R²⁵S, R²⁵SO,R²⁵SO₂, R²⁵NHCO, R²⁵CONH, R²⁵NHSO₂ or R²⁵SO₂NH;

Preferred compounds of the present invention are those compounds of Formula I defined above wherein:

B is selected from

R²(R^(2a))N—,

R²HN(R^(2a)N═)C—,

R²HN(R^(2a)N═)CNH—,

Z¹ and Z² are independently selected from a single bond, C₁-C₆ alkylene, optionally substituted by R^(2b), wherein any carbon atom in the alkylene chain may optionally be replaced with O, with the proviso that O when present is adjacent to saturated or aromatic carbon atoms;

V is selected from

a single bond,

1,4-phenylene; wherein the phenylene group is optionally substituted with 1-2 R⁵ substituents; provided that

B, Z¹, Z² and V are chosen such that the oxime carbon in Formula I is not directly connected to an

oxygen, sulfur or nitrogen atom of B, Z¹ or Z²;

L is a C₁-C₄ alkylene chain, optionally substituted with

C₁-C₄ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

aryl,

arylmethyl;

R¹ is selected from

H,

C₁-C₆ alkyl, substituted with 0-1 R⁶,

C₃-C₇ cycloalkyl, substituted with 0-1 R⁶,

aryl;

R² is selected from

H,

C₁-C₆ alkyl,

arylmethyl;

R⁴ is selected from

H,

C₁-C₆ alkyl,

aryl,

arylmethyl,

OR¹⁴,

NR⁷R⁸,

NR¹¹R¹⁵;

R⁵ is selected from

H,

halo,

C₁-C₄ alkyl,

C₁-C₄ haloalkyl,

C₁-C₄ alkyloxy;

R¹² is selected from

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

aryl,

aryl(C₁-C₄ alkyl),

heteroaryl;

R¹³ is selected from

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

C₁-C₆ haloalkyl,

aryl(C₁-C₄ alkyl);

R¹⁴ is selected from

H,

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

aryl,

aryl(C₁-C₄ alkyl);

R¹⁶ is selected from

C₁-C₈ alkyl, substituted with 0-2 R⁶,

C₂-C₈ alkenyl, substituted with 0-2 R⁶,

C₂-C₈ alkynyl, substituted with 0-2 R⁶,

C₃-C₇ cycloalkyl, substituted with 0-2 R⁶,

aryl,

aryl (C₁-C₄ alkyl),

heteroaryl,

heteroaryl (C₁-C₄ alkyl);

R²¹ and R²² are selected from C₁-C₄ alkyl, or

R²¹ and R²² can be taken together to form a pyrrolidine, piperidine or morpholine ring;

R²³ is selected from C₁-C₄ alkyl;

Y is selected from

OH,

C₁-C₁₀ alkyloxy,

C₃-C₇ cycloalkyloxy,

C₄-C₈ cycloalkyloxy,

arylmethyloxy,

C₁-C₆ alkylcarbonyloxy(C₁-C₄ alkyl)oxy,

C₁-C₆ alkyloxycarbonyloxy(C₁-C₄ alkyl)oxy,

C₃-C₇ cycloalkylcarbonyloxy(C₁-C₄ alkyl)oxy,

C₃-C₇ cycloalkyloxycarbonyloxy(C₁-C₄)oxy,

aryloxycarbonyloxy(C₁-C₄ alkyl)oxy,

arylcarbonyloxy(C₁-C₄ alkyl)oxy,

(C₁-C₂ alkyloxy(C₁-C₄)alkyl)carbonyloxy(C₁-C₂ alkyl)oxy, (5-(C₁-C₄ alkyl)-1,3-dioxa-cyclopenten-2-one-4-yl)methyloxy, (5-phenyl-1,3-dioxa-cyclopenten-2-one-4-yl)methyloxy,

(R²¹)(R²²)N(C₂-C₄ alkyl)oxy-,

(R²¹)(R²²)(R²³)N⁺(C₂-C₄ alkyl)oxy-(X⁻), where X⁻ is a pharmaceutically acceptable anionic group such as halide, sulfate, organosulfonate or organocarboxylate;

and wherein aryl and heteroaryl are defined as before;

More preferred are those preferred compounds defined above wherein:

B is selected from

R²HN(R^(2a)N═)C—,

R²HN(R^(2a)N═)CNH—,

L is a C₁-C₄ alkylene chain, optionally substituted with C₁-C₄ alkyl;

R¹ is selected from

H,

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

aryl;

R² is selected from

H,

C₁-C₆ alkyl,

benzyl;

R^(2a) is selected from

H,

OH

C₁-C₆ alkyloxycarbonyl,

C₃-C₇ cycloalkyloxycarbonyl,

benzyloxycarbonyl,

C₁-C₄ alkylcarbonyloxy(C₁-C₂ alkyl)oxycarbonyl,

C₃-C₈ cycloalkylcarbonyloxy(C₁-C₂ alkyl)oxycarbonyl;

R^(2b) is selected from

H,

C₁-C₆ alkyl;

R³ is selected from

H,

C₁-C₈ alkyl, substituted with 0-R⁶,

C₂-C₈ alkenyl, substituted with 0-1 R⁶,

C₂-C₈ alkynyl, substituted with 0-1 R⁶,

C₃-C₇ cycloalkyl, substituted with 0-1 R⁶,

aryl,

heteroaryl,

CONR⁷R⁸;

R⁴ is selected from

H,

NR¹¹R¹⁵;

R¹¹ is selected from

H,

C₁-C₄ alkyl;

R¹³ is selected from

C₁-C₆ alkyl,

C₃-C₇ cycloalkyl,

C₄-C₈ cycloalkylalkyl,

C₁-C₆ haloalkyl,

arylmethyl;

R¹⁶ is selected from

C₁-C₈ alkyl, substituted with 0-2 R⁶,

aryl,

aryl(C₁-C₄ alkyl);

R¹⁷ is selected from

C₁-C₈ alkyl, substituted with 0-2 R⁶,

aryl(C₁-C₄ alkyl);

R¹⁸ and R¹⁹ are selected from

H,

C₁-C₈ alkyl, substituted with 0-2 R⁶,

aryl,

aryl(C₁-C₄ alkyl);

R²⁰ is selected from

C₁-C₈ alkyl, substituted with 0-2 R⁶,

aryl,

aryl(C₁-C₄ alkyl),

heteroaryl,

heteroaryl(C₁-C₄ alkyl); and

wherein aryl and heteroaryl are as defined before.

Most preferred are those more preferred compounds defined above wherein:

B is selected from:

H₂N(R^(2a)N═)C—,

H₂N(R^(2a)N═)CNH—,

Z¹ and Z² are a single bond;

V is selected from

1,4-phenylene,

wherein the phenylene group is optionally substituted with 1-2 R⁵ substituents;

L is a C₁-C₄ alkylene chain;

R¹ is selected from

H,

C₁-C₆ alkyl;

R² is H;

R^(2a) is selected from

H,

OH

C₁-C₂ alkyloxycarbonyl,

C₅-C₇ cycloalkyloxycarbonyl,

benzyloxycarbonyl,

C₁-C₂ alkylcarbonyloxy(C₁-C₂ alkyl)oxycarbonyl,

C₅-C₆ cycloalkylcarbonyloxy(C₁-C₂ alkyl)oxycarbonyl;

R³ is selected from

H,

C₁-C₆ alkyl,

C₂-C₆ alkenyl,

C₂-C₆ alkynyl,

aryl,

aryl(C₁-C₂ alkyl),

heteroaryl,

heteroaryl(C₁-C₂ alkyl),

CONR⁷R⁸;

R⁵ is selected from

H,

halo,

methyl,

trifluoromethyl,

methoxy;

R¹¹ is H or methyl;

R¹⁵ is selected from

CO₂R¹⁷,

SO₂R²⁰;

R¹⁶ is selected from

C₁-C₈ alkyl, substituted with 0-1 R⁶,

aryl,

aryl(C₁-C₄ alkyl);

R¹⁷ is selected from

C₁-C₈ alkyl, substituted with 0-1 R⁶,

aryl(C₁-C₄ alkyl);

R¹⁸ and R¹⁹ are selected from

H,

C₁-C₈ alkyl, substituted with 0-1 R⁶,

aryl,

aryl(C₁-C₄ alkyl);

R²⁰ is selected from

C₁-C₈ alkyl, substituted with 0-1 R⁶,

aryl,

aryl(C₁-C₄ alkyl),

heteroaryl,

heteroaryl(C₁-C₄ alkyl);

R²¹ and R²² are selected from C₁-C₂ alkyl, or

R²¹ and R²² can be taken together to form a pyrrolidine,

piperidine or morpholine ring;

R²³ is selected from C₁-C₂ alkyl;

Y is selected from

OH,

C₁-C₁₀ alkyloxy,

benzyloxy,

C₁-C₄ alkylcarbonyloxy(C₁-C₂ alkyl)oxy,

C₁-C₄ alkyloxycarbonyloxy(C₁-C₂ alkyl)oxy,

C₅-C₆ cycloalkylcarbonyloxy(C₁-C₂ alkyl)oxy,

C₅-C₆ cycloalkyloxycarbonyloxy(C₁-C₂)oxy,

1-(2-(2-methoxypropyl)carbonyloxy)ethoxy,

(5-methyl-1,3-dioxa-cyclopenten-2-one-4-yl)methyloxy, (5-phenyl-1,3-dioxa-cyclopenten-2-one-4-yl)methyloxy, ((R²¹)(R²²)N)ethoxy-,

((R²¹)(R²²)(R²³)N⁺)ethoxy- (X⁻), where X⁻ is a pharmaceutically acceptable anionic group such as halide, sulfate, organosulfonate or organocarboxylate;

and wherein aryl and heteroaryl are defined as above;

Illustrative compounds of the present invention are those most preferred compounds of Formula I which are:

3-[3-[[(4-amidinophenylmethylene)amino]oxy]-1-oxopropylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]propanoic acid

3-[2-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]propanoic acid

3-[3-[[(4-amidinophenylmethylene)amino]oxy]-1-oxopropylamino]-2-(S)-[n-butyloxycarbonylamino]propanoic acid

3-[2-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[n-butyloxycarbonylamino]propanoic acid

3-[3-[[[1-(4-amidinophenyl)ethylidene]amino]oxy]-1-oxopropylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]propanoic acid

3-[2-[[[1-(4-amidinophenyl)ethylidene]amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]propanoic acid

3-[3-[[[1-(4-amidinophenyl)ethylidene]amino]oxy]-1-oxopropylamino]-2-(S)-[n-butyloxycarbonylamino]propanoic acid

3-[2-[[[1-(4-amidinophenyl)ethylidene]amino]oxy]-1-oxoethylamino]-2-(S)-[n-butyloxycarbonylamino]propanoic acid

and nitrogen-derivatized prodrug forms of these illustrative compounds in which the prodrug moeity is chosen from

OH,

methoxycarbonyl,

ethoxycarbonyl,

cyclohexylcarbonyl,

benzyloxycarbonyl,

methylcarbonyloxymethylcarbonyl,

ethylcarbonyloxylmethylcarbonyl,

cyclohexylcarbonyloxymethylcarbonyl;

and esters of these illustrative compounds chosen from

methyl,

ethyl,

i-propyl,

n-butyl,

i-butyl,

benzyl,

methylcarbonyloxymethyl,

ethylcarbonyloxymethyl,

t-butylcarbonyloxyinethyl,

cyclohexylcarbonyloxymethyl,

cyclohexyloxycarbonyloxymethyl,

t-butyloxycarbonyloxymethyl,

dimethylaminoethyl,

diethylaminoethyl,

pyrrolidinylethyl,

morpholinylethyl,

trimethylammoniumethyl (X⁻);

The compounds of Formula I of the present invention are useful for the treatment (including prevention) of thromboembolic disorders. The term “thromboembolic disorders” as used herein includes conditions involving platelet activation and aggregation, such as arterial or venous cardiovascular or cerebrovascular thromboembolic disorders, including, for example, thrombosis, unstable angina, first or recurrent myocardial infarction, ischemic sudden death, transient ischemic attack, stroke, atherosclerosis, venous thrombosis, deep vein thrombosis, thrombophlebitis, arterial embolism, coronary and cerebral arterial thrombosis, myocardial infarction, cerebral embolism, kidney embolisms, pulmonary embolisms, or such disorders associated with diabetes, comprising administering to a mammal in need of such treatment a therapeutically effective amount of a compound of Formula I described above.

The compounds of the present invention are useful for inhibiting the binding of fibrinogen to blood platelets, inhibiting aggregation of blood platelets, treating thrombus formation or embolus formation, or preventing thrombus or embolus formation in a mammal.

The compounds of the invention may be used as a medicament for blocking fibrinogen from acting at its receptor site in a mammal.

Compounds of the invention may be administered to patients where prevention of thrombosis by inhibiting binding of fibrinogen to the platelet membrane glycoprotein complex IIb/IIIa receptor is desired. They are useful in surgery on peripheral arteries (arterial grafts, carotid endarterectomy) and in cardiovascular surgery where manipulation of arteries and organs, and/or the interaction of platelets with artificial surfaces, leads to platelet aggregation and consumption, and where the aggregated platelets may form thrombi and thromboemboli. The compounds of the present invention may be administered to these surgical patients to prevent the formation of thrombi and thromboemboli.

Extracorporeal circulation is routinely used during cardiovascular surgery in order to oxygenate blood. Platelets adhere to surfaces of the extracorporeal circuit. Adhesion is dependent on the interaction between GPIIb/IIIa on the platelet membranes and fibrinogen adsorbed to the surface of the extracorporeal circuit. Platelets released from artificial surfaces show impaired homeostatic function. The compounds of the invention may be administered to prevent such ex vivo adhesion.

The compounds of the present invention may be used for other ex vivo applications to prevent cellular adhesion in biological samples.

Other applications of these compounds include prevention of platelet thrombosis, thromboembolism, and reocclusion during and after thrombolytic therapy and prevention of platelet thrombosis, thromboembolism and reocclusion after angioplasty of coronary and other arteries and after coronary artery bypass procedures. The compounds of the present invention may also be used to prevent myocardial infarction. The compounds of the present invention are useful as thrombolytics for the treatment of thromboembolic disorders.

The compounds of the present invention can also be administered in combination with one or more additional therapeutic agents select from: anti-coagulant or coagulation inhibitory agents, such as heparin or warfarin; anti-platelet or platelet inhibitory agents, such as aspirin, piroxicam, or ticlopidine; thrombin inhibitors such as boropeptides, hirudin or argatroban; or thrombolytic or fibrinolytic agents, such as plasminogen activators, anistreplase, urokinase, or streptokinase.

The compounds of Formula I of the present invention can be administered in combination with one or more of the foregoing additional therapeutic agents, thereby to reduce the doses of each drug required to achieve the desired therapeutic effect. Thus, the combination treatment of the present invention permits the use of lower doses of each component, with reduced adverse, toxic effects of each component. A lower dosage minimizes the potential of side effects of the compounds, thereby providing an increased margin of safety relative to the margin of safety for each component when used as a single agent. Such combination therapies may be employed to achieve synergistic or additive therapeutic effects for the treatment of thromboembolic disorders.

By “therapeutically effective amount” it is meant an amount of a compound of Formula I that when administered alone or in combination with an additional therapeutic agent to a cell or mammal is effective to prevent or ameliorate the thromboembolic disease condition or the progression of the disease.

By “administered in combination” or “combination therapy” it is meant that the compound of Formula I and one or more additional therapeutic agents are administered concurrently to the mammal being treated. When administered in combination each component may be administered at the same time or sequentially in any order at different points in time. Thus, each component may be administered separately but sufficiently closely in time so as to provide the desired therapeutic effect.

The term anti-coagulant agents (or coagulation inhibitory agents), as used herein, denotes agents that inhibit blood coagulation. Such agents include warfarin (available as Coumadin™) and heparin.

The term anti-platelet agents (or platelet inhibitory agents), as used herein, denotes agents that inhibit platelet function such as by inhibiting the aggregation, adhesion or granular secretion of platelets. Such agents include the various known non-steroidal anti-inflammatory drugs (NSAIDS) such as aspirin, ibuprofen, naproxen, sulindac, indomethacin, mefenamate, droxicam, diclofenac, sulfinpyrazone, and piroxicam, including pharmaceutically acceptable salts or prodrugs thereof. Of the NSAIDS, aspirin (acetylsalicyclic acid or ASA), and piroxicam. Piroxicam is commercially available from Pfizer Inc. (New York, N.Y.), as Feldane™. Other suitable anti-platelet agents include ticlopidine, including pharmaceutically acceptable salts or prodrugs thereof. Ticlopidine is also a preferred compound since it is known to be gentle on the gastro-intestinal tract in use. Still other suitable platelet inhibitory agents include thromboxane-A2-receptor antagonists and thromboxane-A2-synthetase inhibitors, as well as pharmaceutically acceptable salts or prodrugs thereof.

The phrase thrombin inhibitors (or anti-thrombin agents), as used herein, denotes inhibitors of the serine protease thrombin and other inhibitors of thrombin synthesis such as Factor XA. By inhibiting thrombin, various thrombin-mediated processes, such as thrombin-mediated platelet activation (that is, for example, the aggregation of platelets, and/or the granular secretion of plasminogen activator inhibitor-1 and/or serotonin) and/or fibrin formation are disrupted. Such inhibitors include boroarginine derivatives and boropeptides, hirudin and argatroban, including pharmaceutically acceptable salts and prodrugs thereof. Boroarginine derivatives and boropeptides include N-acetyl and peptide derivatives of boronic acid, such as C-terminal a-aminoboronic acid derivatives of lysine, ornithine, arginine, homoarginine and corresponding isothiouronium analogs thereof. The term hirudin, as used herein, includes suitable derivatives or analogs of hirudin, referred to herein as hirulogs, such as disulfatohirudin. Boropeptide thrombin inhibitors include compounds described in Kettner et al., U.S. Pat. No. 5,187,157 and European Patent Application Publication Number 293 881 A2, the disclosures of which are hereby incorporated herein by reference. Other suitable boroarginine derivatives and boropeptide thrombin inhibitors include those disclosed in PCT Application Publication Number 92/07869 and European Patent Application Publication Number 471 651 A2, the disclosures of which are hereby incorporated herein by reference, in their entirety.

The phrase thrombolytics (or fibrinolytic) agents (or thrombolytics or fibrinolytics), as used herein, denotes agents that lyse blood clots (thrombi). Such agents include tissue plasminogen activator, anistreplase, urokinase or streptokinase, including pharmaceutically acceptable salts or prodrugs thereof. Tissue plasminogen activator (tPA) is commercially available from Genentech Inc., South San Francisco, Calif. The term anistreplase, as used herein, refers to anisoylated plasminogen streptokinase activator complex, as described, for example, in European Patent Application No. 028,489, the disclosures of which are hereby incorporated herein by reference herein, in their entirety. Anistreplase is commercially available as Eminase™. The term urokinase, as used herein, is intended to denote both dual and single chain urokinase, the latter also being referred to herein as prourokinase.

Administration of the compounds of Formula I of the invention in combination with such additional therapeutic agent, may afford an efficacy advantage over the compounds and agents alone, and may do so while permitting the use of lower doses of each. A lower dosage minimizes the potential of side effects, thereby providing an increased margin of safety.

GPIIb/IIIa is known to be overexpressed in metastatic tumor cells. The compounds or combination products of the present invention may also be useful for the treatment, including prevention, of metastatic cancer.

The compounds of the present invention are also useful as standard or reference compounds, for example as a quality standard or control, in tests or assays involving the binding of fibrinogen to platelet GPIIb/IIIa. Such compounds may be provided in a commercial kit, for example, for use in pharmaceutical research involving GPIIb/IIIa. The compounds of the present invention may also be used in diagnostic assays involving platelet GPIIb/IIIa.

The compounds herein described may have asymmetric centers. Unless otherwise indicated, all chiral, diastereomeric and racemic forms are included in the present invention. Many geometric isomers of olefins, C═N double bonds, and the like can also be present in the compounds described herein, and all such stable isomers are contemplated in the present invention. It will be appreciated that compounds of the present invention that contain asymmetrically substituted carbon atoms may be isolated in optically active or racemic forms. It is well known in the art how to prepare optically active forms, such as by resolution of racemic forms or by synthesis, from optically active starting materials. All chiral, diastereomeric, racemic forms and all geometric isomeric forms of a structure are intended, unless the specific stereochemistry or isomer form is specifically indicated.

When any variable (for example but not limited to, R¹, R², R^(2a), or R⁴, etc.) occurs more than one time in any constituent or in any formula, its definition on each occurrence is independent of its definition at every other occurrence. Thus, for example, if a group is shown to be substituted with 0-2 R⁶, then said group may optionally be substituted with up to two R⁶ and R⁶ at each occurrence is selected independently from the defined list of possible R⁶.

When a bond to a substituent is shown to cross the bond connecting two atoms in a ring, then such substituent may be bonded to any atom on the ring. When a bond joining a substituent to another group is not specifically shown or the atom in such other group to which the bond joins is not specifically shown, then such substituent may form a bond with any atom on such other group.

When a substituent is listed without indicating the atom via which such substituent is bonded to the rest of the compound of Formula I, then such substituent may be bonded via any atom in such substituent. For example, when the substituent is pyridyl, or pyrozaoly, etc., unless specified otherwise, said pyridyl or pyrazoly, group may be bonded to the rest of the compound of Formula I via any atom in such pyridyl or pyrazoly, group.

Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds. By stable compound or stable structure it is meant herein a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent.

The term “substituted”, as used herein, means that any one or more hydrogen on the designated atom is replaced with a selection from the indicated group, provided that the designated atom's normal valency is not exceeded, and that the substitution results in a stable compound. When a substituent is keto (i.e., ═O), then 2 hydrogens on the atom are replaced.

As used herein, “alkyl” is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms (for example, “C₁-C₈” denotes alkyl having 1 to 8 carbon atoms); “alkyloxy” represents an alkyl group of indicated number of carbon atoms attached through an oxygen bridge; “cycloalkyl” is intended to include saturated ring groups, including mono-, bi-, or poly-cyclic ring systems, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or cycloheptyl. “Alkenyl” is intended to include hydrocarbon chains of either a straight or branched configuration and one or more unsaturated carbon-carbon bonds which may occur in any stable point along the chain, such as ethenyl, propenyl and the like; and “alkynyl” is intended to include hydrocarbon chains of either a straight or branched configuration and one or more triple carbon—carbon bonds which may occur in any stable point along the chain, such as ethynyl, propynyl and the like.

The terms “alkylene”, “alkenylene”, “phenylene”, and the like, refer to alkyl, alkenyl, and phenyl groups, respectively, which are connected by two bonds to the rest of the structure of Formula I. Such “alkylene”, “alkenylene”, “phenylene”, and the like, may alternatively and equivalently be denoted herein as “-(alkyl)-”, “-(alkenyl)-” and “-(phenyl)-”, and the like.

“Halo” or “halogen” as used herein refers to fluoro, chloro, bromo and iodo; and “counterion” is used to represent a small, negatively charged species such as chloride, bromide, hydroxide, acetate, sulfate and the like.

As used herein, “pharmaceutically acceptable salts” refer to derivatives of the disclosed compounds wherein the parent compound of Formula I is modified by making acid or base salts of the compound of Formula I. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like.

“Prodrugs” are considered to be any covalently bonded carriers which release the active parent drug according to Formula I in vivo when such prodrug is administered to a mammalian subject. Prodrugs of the compounds of Formula I are prepared by modifying functional groups present in the compounds in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to the parent compounds. Prodrugs include compounds of Formula I wherein hydroxyl, amino, sulfhydryl, or carboxyl groups are bonded to any group that, when administered to a mammalian subject, cleaves to form a free hydroxyl, amino, sulfhydryl, or carboxyl group respectively. Examples of prodrugs include, but are not limited to, acetate, formate and benzoate derivatives of alcohol and amine functional groups in the compounds of Formula I, and the like. Examples of the prodrug forms of the compounds of the present invention include the following esters:

methyl; ethyl; isopropyl; methylcarbonyloxymethyl-;

ethylcarbonyloxymethyl-; t-butylcarbonyloxymethyl-;

cyclohexylcarbonyloxymethyl-;

1-(methylcarbonyloxy)ethyl-; 1-(ethylcarbonyloxy)ethyl-;

1-(t-butylcarbonyloxy)ethyl-;

i-propyloxycarbonyloxymethyl-;

cyclohexylcarbonyloxymethyl-;

t-butyloxycarbonyloxymethyl-;

1-(i-propyloxycarbonyloxy)ethyl-;

1-(cyclohexyloxycarbonyloxy)ethyl-;

1-(t-butyloxycarbonyloxy)ethyl-; dimethylaminoethyl-;

diethylaminoethyl-; (5-(5-butyl)-1,3-dioxacyclopenten-2-on-4yl)methyl-; (5-(t-butyl)-1,3-dioxacyclopenten-2-on-4-yl)methyl-; (1,3-dioxa-5-phenyl-cyclopenten-2-on-4-yl)methyl-; 1-(2-(2-methyoxypropyl)-carbonyloxy)ethyl-.

The pharmaceutically acceptable salts of the compounds of Formula I include the conventional non-toxic salts or the quaternary ammonium salts of the compounds of Formula I formed, for example, from non-toxic inorganic or organic acids. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxybenzoic, fumaric, benzenesulphnic, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionic, and the like.

The pharmaceutically acceptable salts of the present invention can be synthesized from the compounds of Formula I which contain a basic or acidic moiety by conventional chemical methods. Generally, the salts are prepared by reacting the free base or acid with stoichiometric amounts or with an excess of the desired salt-forming inorganic or organic acid or base in a suitable solvent or various combinations of solvents.

The pharmaceutically acceptable salts of the acids of Formula I with an appropriate amount of a base, such as an alkali or alkaline earth metal hydroxide e.g. sodium, potassium, lithium, calcium, or magnesium, or an organic base such as an amine, e.g., dibenzylethylenediamine, trimethylamine, piperidine, pyrrolidine, benzylamine and the like, or a quaternary ammonium hydroxide such as tetramethylammoinum hydroxide and the like.

As discussed above, pharmaceutically acceptable salts of the compounds of the invention can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid, respectively, in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., 1985, p. 1418, the disclosure of which is hereby incorporated by reference.

The disclosures of all of the references cited herein are hereby incorporated herein by reference in their entirety.

Synthesis

The compounds of the present invention can be synthesized using the methods described below, together with synthetic methods known in the art of synthetic organic chemistry, or variations thereon as appreciated by those skilled in the art. Preferred methods include, but are not limited to, those described below. All references cited herein are hereby incorporated in their entirety herein by reference.

The following abbreviations are used herein:

b-Ala 3-aminopropionic acid Boc tert-butyloxycarbonyl Boc₂O di-tert-butyl dicarbonate BOP benzotriazolyl-N-oxytris(dimethylamino)- phosphonium hexafluorophosphate BSTFA N,O-bis(trimethylsilyl)trifluoromethyl- acetamide Cbz benzyloxycarbonyl DCC 1,3-dicyclohexylcarbodiimide DEAD diethyl azodicarboxylate DEC 1-(3-dimethylaminopropyl)-3- ethylcarbodiimide hydrochloride DIEA diisopropylethylamine DCHA dicyclohexylamine DCM dichloromethane DMAP 4-dimethylaminopyridine DMF N,N-dimethylformamide EtOAc ethyl acetate EtOH ethyl alcohol HOBt 1-hydroxybenzotriazole IBCF iso-butyl chloroformate LAH lithium aluminum hydride NCS N-chlorosuccinimide NMM N-methylmorpholine PPh₃ triphenylphosphine pyr pyridine TBTU 2-(1H-Benzotriazol-1-yl)-1,1,3,3- tetramethyluronium tetrafluoroborate TFA trifluoroacetic acid THF tetrahydrofuran

Scheme I describes one synthetic sequence to the compounds of this invention. In Scheme I, B is as described above or may also represent a precursor to B, such as nitrile or halogen, or a protected version of B. All other abbreviations in Scheme I are as defined above. An appropriately substituted oxime or ketoxime is generated from the appropriate aldehyde or ketone by treatment with hydroxylamine according to standard methods. Alkylation of the oxime in basic conditions, such as t-BuOK or NaH, with appropriate haloalkyl esters affords the O-alkylated oximino derivatives. The ester is then saponified or hydrolyzed to the carboxylic acid using conventional methods known to one skilled in the art of organic synthesis. Intermediates containing alkali-sensitive functionality, such as nitrile, may be deesterified with excellent chemoselectivity using sodium trimethylsilanolate according to the procedure of Laganis and Ehenard (Tetrahedron Lett. 1984, 25, 5831). Coupling of the resulting acids to an appropriately substituted b-amino ester using standard coupling reagents, such as DCC/HOBt or TBTU, affords the desired amide. If B is protected with, for example, Cbz or Boc; it may now be deprotected using methods known to one skilled in the art of organic synthesis. This is followed by conversion of the ester to the carboxylic acid using, for example, LiOH/THF/H₂O or other standard methods. If B is a precursor such as nitrile, as in Scheme Ia, the nitrile is then converted to the amidine via the imidate or thioimidate under standard conditions to give the prodrug esters. This is followed by ester saponification (e.g., LiOH/THF/H₂O), hydrolysis or enzymolysis to give the acids.

An exemplification of the method described in Scheme I is shown in Scheme II. 4-Cyanophenyloxime is treated with t-BuOK in THF and tert-butyl bromoacetate. The resulting tert-butyl 4-cyanophenyloximino-O-alkanoate is hydrolyzed to the acid by treatment with TFA in methylene chloride. The resulting acid is then coupled to an appropriately substituted ester of a beta-amino acid using, for example, TBTU and triethylamine in DMF. The nitrile may then be converted to the amidine by first treating with anhydrous HCl in dry methanol to afford the imidate, followed by treatment of the imidate with ammonium carbonate in dry methanol. The ester may then be saponified using LiOH in methanol/water.

A related method of preparation for compounds of the present invention involves conversion of the 4-cyanophenyloximino-O-alkanoate ester intermediate shown in Scheme II to the corresponding amidine using a Pinner sequence. Protection of the amidine as the Boc-derivative and saponification of the ester group provides the corresponding Boc-amidinophenyoximino-O-alkanoic acid. Coupling with b-amino acid esters and acidic Boc-removal provides the desired oximino-O-alkanoyl-b-aminoalaninyl esters. Saponification as described above gives the free acids.

Oximes of the present invention are prepared from appropriate aldehydes or ketones; these may in turn be prepared by oxidation of the corresponding alcohols. Oximes suitable for use in this invention are described by Wityak et al. (J. Med. Chem. 1997, 40, 50-60) and Xue et al. (J. Med. Chem. 1997, 40, 2064-2084). Alkylation of the oximes may be carried out by treatment of the oxime with a suitable base and an alkylating agent having a suitable leaving group, or by addition of the oxime across a double bond. The alkylating agent may have an ester functionality which may be manipulated as shown in Schemes I and II, or it may already be coupled to an appropriately substituted b-amino acid.

The appropriately substituted racemic b-amino acids may be purchased commercially or, as is shown in Scheme III, Method 1, prepared from the appropriate aldehyde, malonic acid and ammonium acetate according to the procedure of Johnson and Livak (J. Am. Chem. Soc. 1936, 58, 299). Racemic b-substituted-b-amino esters may be prepared through the reaction of dialkylcuprates or alkyllithiums with 4-benzoyloxy-2-azetidinone followed by treatment with anhydrous acid in ethanol (Scheme III, Method 2) or by reductive amination of b-keto esters as is described in WO9316038. (Also see Rico et al., J. Org. Chem. 1993, 58, 7948-51.) Enantiomerically pure b-substituted-b-amino acids can be obtained through the optical resolution of the racemic mixture or can be prepared using numerous methods, including: Arndt-Eistert homologation of the corresponding a-amino acids as shown in Scheme III, Method 3 (see Meier, and Zeller, Angew, Chem. Int. Ed. Engl. 1975, 14, 32; Rodriguez, et al. Tetrahedron Lett. 1990, 31, 5153; Greenlee, J. Med. Chem. 1985, 28, 434 and references cited within); and through an enantioselective hydrogenation of a dehydroamino acid as is shown in Scheme III, Method 4 (see Asymmetric Synthesis, Vol. 5, (Morrison, ed.) Academic Press, New York, 1985). A comprehensive discussion of the preparation of b-amino acid derivatives may be found in patent application WO 9307867, the disclosure of which is hereby incorporated by reference.

The synthesis of N²-substituted diaminopropionic acid derivatives can be carried out via Hoffman rearrangement of a wide variety of asparagine derivatives as described in Synthesis, 266-267, (1981), or from commercially available Z-protected diaminopropionate as described by Xue et al. (J. Med. Chem. 1997, 40, 2064-2084; Bioorg. Med. Chem. Lett. 1996, 6, 339-344; and references cited therein). Xue et al. (J. Med. Chem. 1997, 40, 2064-2084, and references cited therein) describe a variety of methods which may be used for the preparation of b-amino acids suitable for the synthesis of compounds of the present invention.

The following examples are provided to describe the invention in further detail. These examples, which set forth the best mode presently contemplated for carrying out the invention, are intended to illustrate and not to limit the invention.

EXPERIMENTAL EXAMPLE 1 Table Example 12 3-[2-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoic acid TFA salt

Part A: 4-Cyanobenzaldoxime

This material was prepared from 4-cyanobenzaldehyde according to Kawase and Kikugawa (J. Chem. Soc., Perkin Trans I 1979, 643). To a solution of 4-cyanobenzaldehyde (1.31 g, 10 mmol) in 1:1 EtOH:pyridine (10 mL) was added hydroxylamine hydrochloride (0.70 g, 10 mmol). The resulting solution was stirred at room temperature for 18 h and was concentrated in vacuo to one-half volume. To this solution was added ice water, causing the product to crystallize from solution. Recrystallization from EtOH-water followed by drying over P₂O₅ afforded 1.46 g (100%) of the desired oxime; mp: 167.8-169.4_C.

Part B: t-Butyl 2[[(4-cyanophenylmethylene)amino]oxy]acetate

To a solution of 4-cyanobenzaldoxime (500 mg, 3.42 mmol) in tetrahydrofuran (5 mL) was added potassium tert-butoxide (1M solution in THF, 6.84 mL, 6.84 mmol) dropwise. After the resulting mixture had stirred for 20 min., tert-butylbromo-acetate (1.01 mL, 6.84 mmol) was added dropwise and the resulting suspension was stirred at room temperature for 1½ hours. The reaction mixture was then poured into water (100 mL) and extracted with ethyl acetate (100 mL). The organic layer was dried over Na₂SO₄, filtered and evaporated in vacuo. The residue was chromatographed on silica gel (5%-20% EtOAc in Hexane, step gradient) to yield 600 mg of desired product as a white solid. ¹H NMR (CDCl₃, 300 MHz) δ 8.2 (s, 1H), 7.75 (m, 4H), 4.64 (s, 2H), 1.47 (s, 9H).

Part C: 2[[(4-cyanophenylmethylene)amino]oxy]acetic acid

t-Butyl 2[[(4-cyanophenylmethylene)amino]oxy]acetate (480 mg, 1.84 mmol) was dissolved in CH₂Cl₂ (10 mL), and 10 mL of TFA was added. The reaction mixture was stirred at room temperature for 1½ hours. The reaction mixture was evaporated in vacuo to yield 360 mg of an off-white solid. ¹H NMR (DMSO-d₆, 300 MHz) δ 8.46 (s, 1H), 7.84 (dd, 4H), 4.72 (s, 2H).

Part D: Methyl 3-[2-[[(4-cyanophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate

To a solution of 2[[(4-cyanophenylmethylene) amino]oxy]acetic acid (193 mg, 0.945 mmol) in DMF (10 mL) was added methyl-N²-3-methylphenylsulfonyl-(S)-2,3-diaminopropionate HCl salt (262 mg, 0.945 mmol), TBTU (303 mg, 0.945 mmol), and triethylamine (0.26 mL, 1.89 mmol). After stirring at room temperature for 62 hours, the reaction mixture was partitioned between EtOAc (50 mL) and water (100 mL). The water layer was washed once with EtOAc (50 mL). Organic layers were combined and washed with water (50 mL), pH 4 phthalate buffer solution (2×75 mL), 5% NaHCO₃ (100 mL), brine (50 mL), dried (Na₂SO₄), filtered and evaporated in vacuo. The residue was purified by chromatography on silica gel (60%-80% EtOAc/Hexane, step gradient) to yield 180 mg of an amber glass. ¹H NMR (CDCl₃, 300 MHz) δ 8.28 (s, 1H), 7.72 (dd, 4H), 7.57 (m, 2H), 7.39 (m, 2H), 6.79 (bt, 1H), 5.45 (d, 1H), 4.68 (s, 2H), 4.0-3.55 (m, 3H), 3.59 (s, 3H), 2.4 (s, 1H); MS (ESI): m/e 459.1 (M+H)⁺.

Part E: Methyl 3-[2-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methyliphenyl)sulfonylamino]-propanoate TFA salt

Methyl 3-[2-[[(4-cyanophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate (177 mg, 0.386 mmol) was dissolved in 15 mL of anhydrous methanol at 0° C. and a stream of HCl gas was bubbled through the solution for 1½ hours. The reaction vessel was sealed and after stirring at room temperature for 16 hours the volatiles were removed in vacuo. The residue was then diluted with 15 mL of anhydrous methanol, ammonium carbonate (185 mg, 1.93 mmol) was added and after stirring for 16 hours the reaction mixture was concentrated in vacuo to yield the crude hydrochloride salt. The residue was purified by preparative HPLC (Dynamax-300A C₁₈ reverse phase column; 21.4×250 mm; 10 ml/min flow rate; 254 nM; gradient: from 100% H₂O with 0.05% TFA to 20% H₂O and 80% CH₃CN with 0.05% TFA in 50 minutes) to yield 148 mg of desired product as a white solid. ¹H NMR (DMSO-d₆, 300 MHz) δ 9.37 (bs, 2H), 9.1 (bs, 2H), 8.44 (s, 1H), 8.33 (d, 1H), 7.99 (t, 1H), 7.83 (m, 4H), 7.55 (m, 2H), 7.43 (m, 2H), 4.48 (s, 2H), 3.99 (m, 1H), 3.4 (m, 1H), 3.35 (s, 3H), 3.22 (m, 1H), 2.38 (s, 3H).

Part F: 3-[2-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoic acid TFA salt

Methyl 3-[2-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate TFA salt (118 mg, 0.2 mmol) was dissolved in 2 mL of methanol and 0.6 mL of 1M LiOH was added. After stirring at room temperature for 16 hours, the reaction mixture was evaporated in vacuo and the residue was dissolved in 2 mL of 1:1 CH₂Cl₂/TFA. This solution was evaporated in vacuo and the residue was purified by preparative HPLC (Dynamax-300A C₁₈ reverse phase column; 21.4×250 mm; 10 ml/min flow rate; 254 nM; gradient: from 100% H₂O with 0.05% TFA to 20% H₂O and 80% CH₃CN with 0.05% TFA in 50 minutes) to yield 60 mg of desired product as a white solid. ¹H NMR (DMSO-d₆, 300 MHz) δ 9.4 (bs, 2H), 9.19 (bs, 2H), 8.45 (s, 1H), 8.12 (d, 1H), 7.95 (t, 1H), 7.83 (s, 4H), 7.57 (m, 2H), 7.43 (m, 2H), 4.45 (ABquart, 2H), 3.87 (m, 1H), 3.42 (m, 1H), 3.18 (m, 1H), 2.38 (s, 3H); MS (ESI): m/e 462.3 (M+H)⁺; HRMS (FAB), e/z Calc. for (M+H)⁺: 462.144731, Found: 462.144688.

EXPERIMENTAL EXAMPLE 2 Table Example 3 3-[2-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[n-butyloxycarbonylamino]-propanoic acid TFA salt

Part A: Methyl 3-[2-[[(4-cyanophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[n-butyloxycarbonylamino]-propanoate

To a solution of 2[[(4-cyanophenylmethylene) amino]oxy]acetic acid (160 mg, 0.784 mmol) in 15ml of DMF was added methyl N²-n-butyloxycarbonyl-(S)-2,3-diaminopropionate HCl salt (200 mg, 0,784 mmol), TBTU (252 mg, 0.784 mmol), and triethylamine (0.22 mL, 1.57 mmol). After stirring at room temperature for 16 hours, the reaction mixture was partitioned between EtOAc (50 mL) and water (75 mL). The water layer was washed once with EtOAc (50 mL). Organic layers were combined and washed with water (50 mL), pH 4 phthalate buffer solution (2×75 mL), 5% NaHCO₃ (100 mL), brine (50 mL), dried (Na₂SO₄), filtered and evaporated in vacuo. The residue was purified by chromatography on silica gel (60%-80% EtOAc/Hexane, step gradient) to yield 110 mg of a colorless glass. ¹H NMR (CDCl₃, 300 MHz) δ 8.24 (s, 1H), 7.7 (m, 4H), 6.75 (bt, 1H), 5.6 (bd, 1H), 4.68 (s, 2H), 4.42 (m, 1H), 4.2-3.7 (m, 4H), 3.75 (s, 3H), 1.6-1.2 (m, 4H), 0.9 (t, 3H); MS (ESI): m/e 405.2 (M+H)⁺.

Part B: Methyl 3-[2-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[n-butyloxycarbonylamino]-propanoate TFA salt

Methyl 3-[2-[[(4-cyanophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[n-butyloxycarbonylamino]-propanoate (107 mg, 0.265 mmol) was dissolved in 15 mL of anhydrous methanol at 0° C. and a stream of HCl gas was bubbled through the solution for 1½ hours. The reaction vessel was sealed and after stirring at room temperature for 16 hours the volatiles were removed in vacuo. The residue was then diluted with 15 mL of anhydrous methanol, ammonium carbonate (127 mg, 1.325 mmol) was added and after stirring for 16 hours the reaction mixture was concentrated in vacuo to yield the crude hydrochloride salt. The residue was purified by preparative HPLC (Dynamax-300A C₁₈ reverse phase column; 21.4×250 mm; 10 ml/min flow rate; 254 nM; gradient: from 100% H₂O with 0.05% TFA to 20% H₂O and 80% CH₃CN with 0.05% TFA in 50 minutes) to yield 110 mg of desired product as a white solid. ¹H NMR (DMSO-d₆, 300 MHz) δ 9.37 (bs, 2H), 9.09 (bs, 2H), 8.47 (s, 1H), 7.99 (t, 1H), 7.86 (s, 4H), 7.48 (d, 1H), 4.58 (s, 2H), 4.15 (m, 1H), 3.91 (t, 2H), 3.58 (s, 3H), 3.56-3.35 (m, 2H), 1.5 (m, 2H), 1.3 (m, 2H), 0.87 (t, 3H).

Part C: 3-[2-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[n-butyloxycarbonylamino]-propanoic acid TFA salt

Methyl 3-[2-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[n-butyloxycarbonylamino]-propanoate TFA salt (91 mg, 0.17 mmol) was dissolved in 1.5 mL of methanol and 0.51 mL of 1M LiOH was added. After stirring at room temperature for 16 hours, the reaction mixture was evaporated in vacuo and the residue was dissolved in 2 mL of 1:1 CH₂Cl₂/TFA. This solution was evaporated in vacuo and the residue was purified by preparative HPLC (Dynamax-300A C₁₈ reverse phase column; 21.4×250 mm; 10 ml/min flow rate; 254 nM; gradient: from 100% H₂O with 0.05% TFA to 20% H₂O and 80% CH₃CN with 0.05% TFA in 50 minutes) to yield 63 mg of desired product as a white solid. ¹H NMR (DMSO-d₆, 300 MHz) δ 9.39 (bs, 2H), 9.2 (bs, 2H), 8.44 (s, 1H), 7.99 (t, 1H), 7.83 (m, 4H), 7.36 (d, 1H), 4.6 (s, 2H), 4.05 (m, 1H), 3.9 (m, 2H), 3.55 (m, 1H), 3.36 (m, 1H), 1.46 (m, 2H), 1.3 (m, 2H), 0.85 (t, 3H); MS (ESI): m/e 408.2 (M+H)⁺; HRMS (FAB), e/z Calc. for (M+H)⁺: 408.188309, Found: 408.189211.

EXPERIMENTAL EXAMPLE 3 Table Example 28 3-[2[[[1-(4-amidinophenyl)ethylidene]amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoic acid TFA salt

Part A. 4-Cyanoacetophenoneoxime

To a mixture of acetylbenzonitrile (1.21 g, 8.34 mmol) and hydroxylamine hydrochloride (579 mg, 8.34 mmol) in 10 mL of ethanol was added 10 mL of pyridine. After stirring at room temperature overnight the reaction mixture was concentrated to half volume and poured into 75 mL of water to precipitate product. After filtration, the precipitate was washed with water (100 mL) and dried by passing N₂ through the wet cake under vacuum. 1.08 g of an off-white solid were collected. ¹H NMR (CDCl₃, 300 MHz) δ 8.2 (s,1H), 7.7 (m,4H), 2.3 (s,3H).

Part B. t-Butyl 2[[[1-(4-cyanophenyl)ethylidene]amino]oxy]acetate

To a solution of 4-cyanoacetophenoneoxime (512 mg, 3.2 mmol) in tetrahydrofuran (6 mL) was added potassium-tert-butoxide (1M solution in THF, 6.4 mL, 6.4 mmol) dropwise. After the resulting mixture had stirred for 15 min., tert-butylbromoacetate (0.95 mL, 6.4 mmol) was added dropwise and the resulting suspension was stirred at room temperature for 4 hours. The reaction mixture was then poured into water (100 mL) and extracted with ethyl acetate (100 mL). The organic layer was dried over Na₂SO₄, filtered and evaporated in vacuo. The residue was chromatographed on silica gel (30%-60% EtOAc in Hexane, step gradient) to yield 807 mg of desired product. ¹H NMR (CDCl₃, 300 MHz) δ 7.72 (dd, 4H), 4.65 (s, 2H), 2.31 (s, 3H), 1.48 (s, 9H).

Part C: 2[[[1-(4-cyanophenyl)ethylidene]amino]oxy]acetic acid

t-Butyl 2[[[1-(4-cyanophenyl)ethylidene]amino]oxy]acetate (800 mg, 2.92 mmol) was dissolved in 15 mL of 1:1 CH₂Cl₂/TFA. After stirring at room temperature for 2 hours, the reaction mixture was evaporated in vacuo to yield 550 mg of an amber solid. ¹H NMR (CDCl₃, 300 MHz) δ 7.72 (dd, 4H), 4.82 (s, 2H), 2.33 (s, 3H).

Part D: Methyl 3-[2[[[1-(4-cyanophenyl)ethylidene]amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate

To a solution of 2[[[1-(4-cyanophenyl)ethylidene]amino]oxy]acetic acid (230 mg, 1.054 mmol) in DMF (12 mL) was added methyl N²-3-methylphenylsulfonyl-L-2,3-diaminopropionate HCl salt (292 mg, 1.054 mmol), TBTU (338 mg, 1.054 mmol), and triethylamine (0.29 mL, 2.11 mmol). After stirring at room temperature for 16 hours, the reaction mixture was partitioned between EtOAc (50 mL) and water (100 mL). The water layer was washed once with EtOAc (50 mL). Organic layers were combined and washed with water (50 mL), pH 4 phthalate buffer solution (2×75 mL), 5% NaHCO₃ (100 mL), brine (50 mL), dried (Na₂SO₄), filtered and evaporated in vacuo. The residue was purified by chromatography on silica gel (60%-80% EtOAc/Hexane, step gradient) to yield 257 mg. ¹H NMR (CDCl₃, 300 MHz) δ 7.75 (dd, 4H), 7.55 (m, 2H), 7.38 (m, 2H), 6.78 (bt, 1H), 5.42 (d, 1H), 4.7 (s, 2H), 3.95 (m, 1H), 3.79 (m, 1H), 3.6 (m, 1H), 3.58 (s, 3H), 2.41 (s, 3H), 2.39 (s, 3H).

Part E: Methyl 3-[2[[[1-(4-amidinophenyl)ethylidene]amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate TFA salt

Methyl 3-[2[[[1-(4-cyanophenyl)ethylidene]amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate (252 mg, 0.533 mmol) was dissolved in 15 mL of anhydrous methanol at 0° C. and a stream of HCl gas was bubbled through the solution for 1½ hours. The reaction vessel was sealed and after stirring at room temperature for 16 hours the volatiles were removed in vacuo. The residue was then diluted with 20 mL of anhydrous methanol, ammonium carbonate (256 mg, 2.67 mmol) was added and after stirring for 16 hours the reaction mixture was concentrated in vacuo to yield the crude hydrochloride salt. The residue was purified by preparative HPLC (Dynamax-300A C₁₈ reverse phase column; 21.4×250 mm; 10 ml/min flow rate; 254 nM; gradient: from 100% H₂O with 0.05% TFA to 20% H₂O and 80% CH₃CN with 0.05% TFA in 50 minutes) to yield 303 mg of desired product as an off-white solid.

Part F: 3-[2[[[1-(4-amidinophenyl)ethylidene]amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoic acid TFA salt

Methyl 3-[2[[[1-(4-amidinophenyl)ethylidene]amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate TFA salt (93 mg, 0.177 mmol) was dissolved in 5 mL of methanol and 22.2 mg (0.53 mmol) of LiOH was added as a solution in 2 mL of water. After stirring at room temperature for 16 hours, the reaction mixture was evaporated in vacuo and the residue was dissolved in 4 mL of 1:1 CH₂Cl₂/TFA. This solution was evaporated in vacuo and the residue was purified by preparative HPLC (Dynamax-300A C₁₈ reverse phase column; 21.4×250 mm; 10 ml/min flow rate; 254 nM; gradient: from 100% H₂O with 0.05% TFA to 20% H₂O and 80% CH₃CN with 0.05% TFA in 50 minutes) to yield 35 mg of desired product as a white solid. ¹H NMR (DMSO-d₆, 300 MHz) δ 9.38 (bs, 2H), 9.08 (bs, 2H), 8.16 (d, 1H), 7.86 (dd, 4H), 7.79 (t, 1H), 7.55 (m, 2H), 7.42 (m, 2H), 4.44 (ABquart, 2H), 3.9 (m, 1H), 3.45 (m, 1H), 3.15 (m, 1H), 2.35 (s, 3H), 2.31 (s, 3H); MS (ESI): m/e 476.2 (M+H)⁺; HRMS (FAB), e/z Calc. for (M+H)⁺: 476.160381, Found: 476.161480.

EXPERIMENTAL EXAMPLE 4 Table Example 42 3-[3-[[(4-amidinophenylmethylene)amino]oxy]-1-oxopropylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoic acid TFA salt

Part A. Methyl 3-[[(4-cyanophenylmethylene)amino]oxy]propanoate

To a solution of 4-cyanobenzaldoxime (1 g, 6.84 mmol) in 20 mL of tetrahydrofuran was added 410 mg of sodium hydride (60% by wt. dispersion in mineral oil, 10.26 mmol). After 10 minutes was added methyl-3-bromopropionate (1.12 mL, 10.26 mmol) and the resulting reaction mixture was stirred at room temperature for 4 hours. The reaction mixture was evaporated in vacuo and the residue was chromatographed on silica gel (10%-30% EtOAc/Hexane) to yield 1.09 g of a white solid. ¹H NMR (CDCl₃, 300 MHz) δ 8.07 (s, 1H), 7.65 (s, 4H), 4.48 (t, 2H), 3.72 (s, 3H), 2.78 (t, 2H).

Part B. 3-[[(4-cyanophenylmethylene)amino]oxy]-propanoic acid

To a solution of methyl Methyl 3[[(4-cyanophenylmethylene)amino]oxy]propanoate (786 mg, 3.38 mmol) in 10 mL of tetrahydrofuran was added 426 mg (10.14 mmol) of LiOH as a solution in 5 mL of water. 2 mL of methanol was added to the mixture and the resultant reaction mixture was stirred at room temperature for 16 hours. The reaction mixture was partitioned between EtOAc (100 mL) and 1N HCl (50 mL). The EtOAc layer was washed with brine (50 mL), dried (MgSO₄), filtered and evaporated in vacuo to yield 690 mg of an off-white solid. ¹H NMR (CDCl₃, 300 MHz) δ 8.35 (s, 1H), 7.8 (dd, 4H), 4.36 (t, 2H), 2.64 (t, 2H).

Part C. Methyl 3-[3-[[(4-cyanophenylmethylene)amino]oxy]-1-oxopropylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate

To a solution of 3-[[(4-cyanophenylmethylene)amino]oxy]propanoic acid (340 mg, 1.56 mmol) in DMF (20 mL) was added methyl N²-3-methylphenyl-sulfonyl-L-2,3-diaminopropionate HCl salt (481 mg, 1.56 mmol), TBTU (501 mg, 1.56 mmol), and triethylamine (0.43 mL, 3.12 mmol). After stirring at room temperature for 16 hours, the reaction mixture was partitioned between EtOAc (50 mL) and water (100 mL). The water layer was washed once with EtOAc (50 mL). Organic layers were combined and washed with water (50 mL), 10% citric acid(75 mL), 5% NaHCO₃ (100 mL), brine (50 mL), dried (MgSO₄), filtered and evaporated in vacuo. The residue was purified by chromatography on silica gel (30%-70% EtOAc/Hexane, step gradient) to yield 153 mg of a yellowish solid. ¹H NMR (DMSO-d₆, 300 MHz) δ 8.3 (s, 1H), 8.08 (t, 1H), 7.83 (dd, 4H), 7.55 (m, 2H), 7.43 (m, 2H), 4.27 (t, 2H); MS (ESI): m/e 473.3 (M+H)⁺.

Part D: Methyl 3-[3-[[(4-amidinophenylmethylene)amino]oxy]-1-oxopropylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate TFA salt

Methyl 3-[3-[[(4-cyanophenylmethylene)amino]oxy]-1-oxopropylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate (150 mg, 0.317 mmol) was dissolved in 15 mL of anhydrous methanol at 0° C. and a stream of HCl gas was bubbled through the solution for 1½ hours. The reaction vessel was sealed and after stirring at room temperature for 16 hours the volatiles were removed in vacuo. The residue was then diluted with 15 mL of anhydrous methanol, ammonium carbonate (153 mg, 1.59 mmol) was added and after stirring for 16 hours the reaction mixture was concentrated in vacuo to yield the crude hydrochloride salt. The residue was purified by preparative HPLC (Dynamax-300A C₁₈ reverse phase column; 21.4×250 mm; 10 ml/min flow rate; 254 nM; gradient: from 100% H₂O with 0.05% TFA to 20% H₂O and 80% CH₃CN with 0.05% TFA in 50 minutes) to yield 107 mg of desired product as a white solid. ¹H NMR (DMSO-d₆, 300 MHz) δ 9.35 (bs, 2H), 9.07 (bs, 2H), 8.32 (s, 1H), 8.3 (d, 1H), 8.09 (t, 1H), 7.83 (m, 4H), 7.55 (m, 2H), 7.44 (m, 2H), 4.29 (t, 2H), 3.95 (m, 1H), 3.37 (s, 3H), 3.33 (m, 1H), 3.15 (m, 1H), 2.43 (m, 2H), 2.38 (s, 3H).

Part E: 3-[3-[[(4-amidinophenylmethylene)amino]oxy]-1-oxopropylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoic acid TFA salt

Methyl 3-[3-[[(4-amidinophenylmethylene)amino]oxy]-1-oxopropylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]-propanoate TFA salt (90 mg, 0.15 mmol) was dissolved in 10 mL of 6N HCl and stirred at room temperature for 24 hours. The reaction mixture was evaporated in vacuo and the residue was purified by preparative HPLC (Dynamax-300A C₁₈ reverse phase column; 21.4×250 mm; 10 ml/min flow rate; 254 nM; gradient: from 100% H₂O with 0.05% TFA to 20% H₂O and 80% CH₃CN with 0.05% TFA in 50 minutes) to yield 33 mg of a white solid. ¹H NMR (DMSO-d₆, 300 MHz) δ 9.42 (bs, 2H), 9.19 (bs, 2H), 8.33 (s, 1H), 8.1 (m, 2H), 7.93 (ABquart, 4H), 7.58 (m, 2H), 7.43 (m, 2H), 4.28 (t, 2H), 3.87 (m, 1H), 3.35 (m, 1H), 3.12 (m, 1H), 2.4 (m, 2H), 2.38 (s, 3H). MS (ESI): m/e 476.4 (M+H)⁺; HRMS (FAB), e/z Calc. for (M+H)⁺: 476.160381, Found: 476.161375.

Using the above methods and variations thereof known in the art of organic synthesis, the other examples of compounds shown in Tables 1-2 can be prepared.

TABLE I

Ex. MS No. R¹ n R³ R⁴ Y (M + H)⁺ 1 H 1 H H OH 2 H 1 H NHCO₂nC₄H₉ OMe 3 H 1 H NHCO₂nC₄H₉ OH 408.2^(a) 4 H 1 H NHCO₂iBu OH 5 H 1 H NHSO₂CH₂CH₂cPr OH 6 H 1 H NHCO₂CH₂Ph OH 7 H 1 H NHSO₂nC₄H₉ OH 8 H 1 H NHSO₂Ph OH 9 H 1 H NHSO₂(4-biphenyl) OH 10 H 1 H NHSO₂(2-MePh) OH 11 H 1 H NHSO₂(3-MePh) OMe 12 H 1 H NHSO₂(3-MePh) OH 462.3^(a) 13 H 1 H NHSO₂(4-MePh) OH 14 H 1 H NHSO₂(2,6- diMePh) 15 H 1 H NHSO₂(2,4,6- triMeph) 16 H 1 H NHSO₂(2-BrPh) OH 17 H 1 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 18 CH₃ 1 H H OH 19 CH₃ 1 H NHCO₂nC₄H₉ OMe 20 CH₃ 1 H NHCO₂nC₄H₉ OH 21 CH₃ 1 H NHCO₂iBu OH 22 CH₃ 1 H NHSO₂CH₂CH₂cPr OH 23 CH₃ 1 H NHCO₂CH₂Ph OH 24 CH₃ 1 H NHSO₂nC₄H₉ OH 25 CH₃ 1 H NHSO₂Ph OH 26 CH₃ 1 H NHSO₂(2-MePh) OH 27 CH₃ 1 H NHSO₂(3-MePh) OMe 28 CH₃ 1 H NHSO₂(3-MePh) OH 476.2^(a) 29 CH₃ 1 H NHSO₂(4-MePh) OH 30 CH₃ 1 H NHSO₂(2-BrPh) OH 31 CH₃ 1 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 32 H 2 H H OH 33 H 2 H NHCO₂nC₄H₉ OMe 34 H 2 H NHCO₂nC₄H₉ OH 422.4^(a) 35 H 2 H NHCO₂iBu OH 36 H 2 H NHSO₂CH₂CH₂cPr OH 37 H 2 H NHCO₂CH₂Ph OH 38 H 2 H NHSO₂nC₄H₉ OH 39 H 2 H NHSO₂Ph OH 40 H 2 H NHSO₂(2-MePh) OH 41 H 2 H NHSO₂(3-MePh) OMe 42 H 2 H NHSO₂(3-MePh) OH 476.4^(a) 43 H 2 H NHSO₂(4-MePh) OH 44 H 2 H NHSO₂(2-BrPh) OH 45 H 2 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 46 CH₃ 2 H H OH 47 CH₃ 2 H NHCO₂nC₄H₉ OMe 48 CH₃ 2 H NHCO₂nC₄H₉ OH 436.4a 49 CH₃ 2 H NHCO₂iBu OH 50 CH₃ 2 H NHSO₂CH₂CH₂cPr OH 51 CH₃ 2 H NHCO₂CH₂Ph OH 52 CH₃ 2 H NHSO₂nC₄H₉ OH 53 CH₃ 2 H NHSO₂Ph OH 54 CH₃ 2 H NHSO₂(2-MePh) OH 55 CH₃ 2 H NHSO₂(3-MePh) OMe 56 CH₃ 2 H NHSO₂(3-MePh) OH 57 CH₃ 2 H NHSO₂(4-MePh) OH 58 CH₃ 2 H NHSO₂(2-BrPh) OH 59 CH₃ 2 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 60 H 3 H H OH 61 H 3 H NHCO₂nC₄H₉ OMe 62 H 3 H NHCO₂nC₄H₉ OH 63 H 3 H NHCO₂iBu OH 64 H 3 H NHSO₂CH₂CH₂CPr OH 65 H 3 H NHCO₂CH₂Ph OH 66 H 3 H NHSO₂nC₄H₉ OH 67 H 3 H NHSO₂Ph OH 68 H 3 H NHSO₂(2-MePh) OH 69 H 3 H NHSO₂(3-MePh) OMe 70 H 3 H NHSO₂(3-MePh) OH 71 H 3 H NHSO₂(4-MePh) OH 72 H 3 H NHSO₂(2-BrPh) OH 73 H 3 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 74 CH₃ 3 H H OH 75 CH₃ 3 H NHCO₂nC₄H₉ OMe 76 CH₃ 3 H NHCO₂nC₄H₉ OH 77 CH₃ 3 H NHCO₂iBu OH 78 CH₃ 3 H NHSO₂CH₂CH₂cPr OH 79 CH₃ 3 H NHCO₂CH₂Ph OH 80 CH₃ 3 H NHSO₂nC₄H₉ OH 81 CH₃ 3 H NHSO₂Ph OH 82 CH₃ 3 H NHSO₂(2-MePh) OH 83 CH₃ 3 H NHSO₂(3-MePh) OMe 84 CH₃ 3 H NHSO₂(3-MePh) OH 85 CH₃ 3 H NHSO₂(4-MePh) OH 86 CH₃ 3 H NHSO₂(2-BrPh) OH 87 CH₃ 3 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 88 cycloP 1 H H OH r 89 cycloP 1 H NHCO₂nC₄H₉ OH r 90 cycloP 1 H NHSO₂(2-MePh) OH r 91 cycloP 1 H NHSO₂(3-MePh) OH r 92 cycloP 1 H NHSO₂(2-BrPh) OH r 93 cycloP 1 H NHSO₂(3,5-diMe-4- OH r isoxazolyl) 94 cycloP 2 H H OH r 95 cyclop 2 H NHCO₂nC₄H₉ OH r 96 cyclop 2 H NHSO₂(2-MePh) OH r 97 cycloP 2 H NHSO₂(3-MePh) OH r 98 cycloP 2 H NHSO₂(2-BrPh) OH r 99 cycloP 2 H NHSO₂(3,5-diMe-4- OH r isoxazolyl) 100 Ph 1 H H OH 101 Ph 1 H NHCO₂nC₄H₉ OH 102 Ph 1 H NHSO₂(2-MePh) OH 103 Ph 1 H NHSO₂(3-MePh) OH 104 Ph 1 H NHS02(2-BrPh) OH 105 Ph 1 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 106 Ph 2 H H OH 107 Ph 2 H NHCO₂nC₄H₉ OH 108 Ph 2 H NHSO₂(2-MePh) OH 109 Ph 2 H NHSO₂(3-MePh) OH 110 Ph 2 H NHSO₂(2-BrPh) OH 111 Ph 2 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 112 CH₂Ph 1 H H OH 113 CH₂Ph 1 H NHCO₂nC₄H₉ OH 114 CH₂Ph 1 H NHSO₂(2-MePh) OH 115 CH₂Ph 1 H NHSO₂(3-MePh) OH 116 CH₂Ph 1 H NHSO₂(2-BrPh) OH 117 CH₂Ph 1 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 118 CH₂Ph 2 H H OH 119 CH₂Ph 2 H NHCO₂nC₄H₉ OH 120 CH₂Ph 2 H NHSO₂(2-MePh) OH 121 CH₂Ph 2 H NHSO₂(3-MePh) OH 122 CH₂Ph 2 H NHSO₂(2-BrPh) OH 123 CH₂Ph 2 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 124 H 1 H NH2 OH 125 H 1 H NHCOnBu OH 126 H 1 H NHCOPh OH 127 H 1 H NHCOCH₂Ph OH 128 H 1 H NHCONHnBu OH 129 H 1 H NHSO₂NHPh OH 130 H 2 H NH₂ OH 131 H 2 H NHCOnBU OH 132 H 2 H NHCOPh OH 133 H 2 H NHCOCH₂Ph OH 134 H 2 H NHCONHnBU OH 135 H 2 H NHSO₂NHPh OH 136 CH₃ 1 H NH₂ OH 137 CH₃ 1 H NHCOnBu OH 138 CH₃ 1 H NHCOPh OH 139 CH₃ 1 H NHCOCH₂Ph OH 140 CH₃ 1 H NHCONHnBu OH 141 CH₃ 1 H NHSO₂NHPh OH 142 CH₃ 2 H NH₂ OH 143 CH₃ 2 H NHCOnBu OH 144 CH₃ 2 H NHCOPh OH 145 CH₃ 2 H NHCOCH₂Ph OH 146 CH₃ 2 H NHCONHnBu OH 147 CH₃ 2 H NHSO₂NHPh OH 148 H 1 Me H OH 149 H 1 Et H OH 150 H 1 Ph H OH 151 H 1 acetylenyl H OH 152 H 1 3-pyridyl H OH 153 H 2 Me H OH 154 H 2 Et H OH 155 H 2 Ph H OH 156 H 2 acetylenyl H OH 157 H 2 3-pyridyl H OH 158 H 3 Me H OH 159 H 3 Et H OH 160 H 3 Ph H OH 161 H 3 acetylenyl H OH 162 H 3 3-pyridyl H OH 163 CH₃ 1 Me H OH 164 CH₃ 1 Et H OH 165 CH₃ 1 Ph H OH 166 CH₃ 1 acetylenyl H OH 167 CH₃ 1 3-pyridyl H OH 168 CH₃ 2 Me H OH 169 CH₃ 2 Et H OH 170 CH₃ 2 Ph H OH 171 CH₃ 2 acetylenyl H OH 172 CH₃ 2 3-pyridyl H OH 173 CH₃ 3 Me H OH 174 CH₃ 3 Et H OH 175 CH₃ 3 Ph H OH 176 CH₃ 3 acetylenyl H OH 177 CH₃ 3 3-pyridyl H OH ^(a)Parent molecular ion of TFA salt

TABLE II

Ex. MS No. R¹ n R³ R⁴ Y (M + H)⁺ 300 H 1 H H OH 301 H 1 H NHCO₂nC₄H₉ OH 302 H 1 H NHCO₂iBu OH 303 H 1 H NHSO₂CH₂CH₂cPr OH 304 H 1 H NHCO₂CH₂Ph OH 305 H 1 H NHSO₂nC₄H₉ OH 306 H 1 H NHSO₂Ph OH 307 H 1 H NHSO₂(4-biphenyl) 308 H 1 H NHSO₂(2-MePh) OH 309 H 1 H NHSO₂(3-MePh) OH 310 H 1 H NHSO₂(4-MePh) OH 311 H 1 H NHSO₂(2,6-diMeph) 312 H 1 H NHSO₂(2,4,6- triMeph) 313 H 1 H NHSO₂(2-BrPh) OH 314 H 1 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 315 CH₃ 1 H H OH 316 CH₃ 1 H NHCO₂nC₄H₉ OH 317 CH₃ 1 H NHCO₂iBu OH 318 CH₃ 1 H NHSO₂CH₂CH₂cPr OH 319 CH₃ 1 H NHCO₂CH₂Ph OH 320 CH₃ 1 H NHSO₂nC₄H₉ OH 321 CH₃ 1 H NHSO₂Ph OH 322 CH₃ 1 H NHSO₂(2-MePh) OH 323 CH₃ 1 H NHSO₂(3-MePh) OH 324 CH₃ 1 H NHSO₂(4-MePh) OH 325 CH₃ 1 H NHSO₂(2-BrPh) OH 326 CH₃ 1 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 327 H 2 H H OH 328 H 2 H NHCO₂nC₄H₉ OH 329 H 2 H NHCO₂iBu OH 330 H 2 H NHSO₂CH₂CH₂cPr OH 331 H 2 H NHCO₂CH₂Ph OH 332 H 2 H NHSO₂nC₄H₉ OH 333 H 2 H NHSO₂Ph OH 334 H 2 H NHSO₂(2-MePh) OH 335 H 2 H NHSO₂(3-MePh) OH 336 H 2 H NHSO₂(4-MePh) OH 337 H 2 H NHSO₂(2-BrPh) OH 338 H 2 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 339 CH₃ 2 H H OH 340 CH₃ 2 H NHCO₂nC₄H₉ OH 341 CH₃ 2 H NHCO₂iBu OH 342 CH₃ 2 H NHSO₂CH₂CH₂cPr OH 343 CH₃ 2 H NHCO₂CH₂Ph OH 344 CH₃ 2 H NHSO₂nC₄H₉ OH 345 CH₃ 2 H NHSO₂Ph OH 346 CH₃ 2 H NHSO₂(2-MePh) OH 347 CH₃ 2 H NHSO₂(3-MePh) OH 348 CH₃ 2 H NHSO₂(4-MePh) OH 349 CH₃ 2 H NHSO₂(2-BrPh) OH 350 CH₃ 2 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 351 H 3 H H OH 352 H 3 H NHCO₂nC₄H₉ OH 353 H 3 H NHCO₂iBu OH 354 H 3 H NHSO₂CH₂CH₂cPr OH 355 H 3 H NHCO₂CH₂Ph OH 356 H 3 H NHSO₂nC₄H₉ OH 357 H 3 H NHSO₂Ph OH 358 H 3 H NHSO₂(2-MePh) OH 359 H 3 H NHSO₂(3-MePh) OH 360 H 3 H NHSO₂(4-MePh) OH 361 H 3 H NHSO₂(2-BrPh) OH 362 H 3 H NHSO₂(3,5-diMe-4- OH isoxazolyl) 363 CH₃ 3 H H OH 364 CH₃ 3 H NHCO₂nC₄H₉ OH 365 CH₃ 3 H NHCO₂iBu OH 366 CH₃ 3 H NHSO₂CH₂CH₂cPr OH 367 CH₃ 3 H NHCO₂CH₂Ph OH 368 CH₃ 3 H NHSO₂nC₄H₉ OH 369 CH₃ 3 H NHSO₂Ph OH 370 CH₃ 3 H NHSO₂(2-MePh) OH 371 CH₃ 3 H NHSO₂(3-MePh) OH 372 CH₃ 3 H NHSO₂(4-MePh) OH 373 CH₃ 3 H NHSO₂(2-BrPh) OH 374 CH₃ 3 H NHSO₂(3,5-diMe-4- OH isoxazolyl)

Utility

The compounds of this invention possess antiplatelet efficacy, as evidenced by their activity in standard platelet aggregation assays or platelet fibrinogen binding assays, as described below. A compound is considered to be active in these assays if it has an IC₅₀ value of less than about 1 mM. Platelet aggregation and fibrinogen binding assays which may be used to demonstrate the antiplatelet activity of the compounds of the invention are described below.

Platelet Aggregation Assay:

Venous blood was obtained from the arm of a healthy human donor who was drug-free and aspirin-free for at least two weeks prior to blood collection. Blood was collected into 10 mL citrated Vacutainer tubes. The blood was centrifuged for 15 minutes at 150×g at room temperature, and platelet-rich plasma (PRP) was removed. The remaining blood was centrifuged for 15 minutes at 1500×g at room temperature, and platelet-poor plasma (PPP) was removed. Samples were assayed on a aggregometer (PAP-4 Platelet Aggregation Profiler), using PPP as the blank (100% transmittance). 200 μL of PRP was added to each micro test tube, and transmittance was set to 0%. 20 μL of various agonists (ADP, collagen, arachidonate, epinephrine, thrombin) were added to each tube, and the aggregation profiles were plotted (% transmittance versus time). The results are expressed as % inhibition of agonist-induced platelet aggregation. For the IC₅₀ evaluation, the test compounds were added at various concentrations prior to the activation of the platelets.

Ester prodrugs were preincubated (10⁻³ M F.C.) with 100 IU/mL Porcine liver esterase (Sigma Chemical Co., St. Louis, Mo., #E-3128) for 2 hours at 37° C. Aliquots are then diluted in 0.1 M Tris, pH 7.4, to the desired concentrations. Aliquots of 20 μl of the esterase pretreated prodrugs are added to 200 μl of human platelet rich plasma. Samples were placed in platelet profiler (aggregometer) for 8 minutes at 37° C., followed by the addition of 100 μM Adenosine Diphosphate, (Sigma Chemical Co., St. Louis, Mo., #A-6521), to induce platelet aggregation. Platelet aggregation was allowed to proceed for 5 minutes. Percent inhibition is calculated using percent aggregation in the presence of the test compound divided by percent aggregation of control, times 100. This value is subtracted from 100, yielding percent inhibition. Calculation of IC₅₀ is performed on a Texas Instruments TI59 with an IC₅₀ program.

Purified GPIIb/IIIa-Fibrinogen Binding ELISA

The following reagents are used in the GPIIb/IIIa-fibrinogen binding ELISA:

purified GPIIb/IIIa (148.8 μg/mL);

biotinylated fibrinogen (˜1 mg/mL or 3000 nM);

anti-biotin alkaline phosphatase conjugate (Sigma no. A7418);

flat-bottom, high binding, 96-well plates (Costar Cat. no. 3590);

phosphatase substrate (Sigma 104) (40 mg capsules);

bovine serum albumin (BSA) (Sigma no. A3294);

Alkaline Phosphatase buffer−0.1 M glycine-HCl, 1 mM MgCl₂.6H₂O, 1 mM ZnCl₂, pH 10.4;

Binding buffer−20 mM Tris-HCl, 150 mM NaCl, 1 mM CaCl₂.2H₂O, 0.02% NaN₃, pH 7.0;

Buffer A−50 mM Tris-HCl, 100 mM NaCl, 2 mM CaCl₂.2H₂O, 0.02% NaN₃, pH 7.4;

Buffer A+3.5% BSA (Blocking buffer);

Buffer A+0.1% BSA (Dilution buffer); 2N NaOH.

The following method steps are used in the GPIIb/IIIa-fibrinogen binding ELISA:

Coat plates with GPIIb/IIIa in Binding buffer (125 ng/100 μL/well) overnight at 4° C. (Leave first column uncoated for non-specific binding). Cover and freeze plates at −70° C. until used. Thaw plate 1 hour at room temperature or overnight at 4° C. Discard coating solution and wash once with 200 μL Binding buffer per well. Block plate 2 hours at room temperature on shaker with 200 μL Buffer A+3.5% BSA (Blocking buffer) per well. Discard Blocking buffer and wash once with 200 μL Buffer A+0.1% BSA (Dilution buffer) per well. Pipet 11 μL of test compound (10× the concentration to be tested in Dilution buffer) into duplicate wells. Pipet 11 μL Dilution buffer into non-specific and total binding wells. Add 100 μL Biotinylated fibrinogen (1/133 in Dilution buffer, final concentration=20 nM) to each well. Incubate plates for 3 hours at room temperature on a plate shaker. Discard assay solution and wash twice with 300 μL Binding buffer per well. Add 100 mL Anti-biotin alkaline phosphatase conjugate (1/1500 in Dilution buffer) to each well. Incubate plates for 1 hour at room temperature on plate shaker. Discard conjugate and wash twice with 300 51 Binding buffer per well. Add 100 μL Phosphatase substrate (1.5 mg/mL in Alkaline phosphatase buffer) to each well. Incubate plate at room temperature on shaker until color develops. Stop color development by adding 25 μL 2N NaOH per well. Read plate at 405 nm. Blank against non-specific binding (NSB) well. % Inhibition is calculated as 100—(Test Compound Abs/Total Abs)×100.

Platelet-Fibrinogen Binding Assay:

Binding of ¹²⁵I-fibrinogen to platelets was performed as described by Bennett et al. (1983) Proc. Natl. Acad. Sci. USA 80: 2417-2422, with some modifications as described below. Human PRP (h-PRP) was applied to a Sepharose column for the purification of platelet fractions. Aliquots of platelets (5×10⁸ cells) along with 1 mM calcium chloride were added to removable 96 well plates prior to the activation of the human gel purified platelets (h-GPP). Activation of the human gel purified platelets was achieved using ADP, collagen, arachidonate, epinephrine, and/or thrombin in the presence of the ligand, ¹²⁵I-fibrinogen. The 125I-fibrinogen bound to the activated platelets was separated from the free form by centrifugation and then counted on a gamma counter. For an IC₅₀ evaluation, the test compounds were added at various concentrations prior to the activation of the platelets.

The compounds of Formula I of the present invention may also possess thrombolytic efficacy, that is, they are capable of lysing (breaking up) already formed platelet-rich fibrin blood clots, and thus are useful in treating a thrombus formation, as evidenced by their activity in the tests described below. Preferred compounds of the present invention for use in thrombolysis include those compounds having an IC₅₀ value (that is, the molar concentration of the compound capable of achieving 50% clot lysis) of less than about 1 μM, more preferably an IC₅₀ value of less than about 0.1 μM.

Thrombolytic Assay:

Venous blood was obtained from the arm of a healthy human donor who was drug-free and aspirin free for at least two weeks prior to blood collection, and placed into 10 ml citrated Vacutainer tubes. The blood was centrifuged for 15 minutes at 1500×g at room temperature, and platelet rich plasma (PRP) was removed. To the PRP was then added 1×10⁻³ M of the agonist ADP, epinephrine, collagen, arachidonate, serotonin or thrombin, or a mixture thereof, and the PRP incubated for 30 minutes. The PRP was centrifuged for 12 minutes at 2500×g at room temperature. The supernatant was then poured off, and the platelets remaining in the test tube were resuspended in platelet poor plasma (PPP), which served as a plasminogen source. The suspension was then assayed on a Coulter Counter (Coulter Electronics, Inc., Hialeah, Fla.), to determine the platelet count at the zero time point. After obtaining the zero time point, test compounds were added at various concentrations. Test samples were taken at various time points and the platelets were counted using the Coulter Counter. To determine the percent of lysis, the platelet count at a time point subsequent to the addition of the test compound was subtracted from the platelet count at the zero time point, and the resulting number divided by the platelet count at the zero time point. Multiplying this result by 100 yielded the percentage of clot lysis achieved by the test compound. For the IC₅₀ evaluation, the test compounds were added at various concentrations, and the percentage of lysis caused by the test compounds was calculated.

The compounds of Formula I of the present invention are also useful for administration in combination with anti-coagulant agents such as warfarin or heparin, or antiplatelet agents such as aspirin, piroxicam or ticlopidine, or thrombin inhibitors such as boropeptides, hirudin or argatroban, or thrombolytic agents such as tissue plasminogen activator, anistreplase, urokinase or streptokinase, or combinations thereof.

The compounds of Formula I of the present invention may also be useful as antagonists of other integrins such as for example, the a_(v)/b₃ or vitronectin receptor, a₄/b₁ or a₅/b₁ and as such may also have utility in the treatment and diagnosis of osteoporosis, cancer metastasis, diabetic retinopathy, rheumatoid arthritis, inflammation, and autoimmune disorders. The compounds of Formula I of the present invention may be useful for the treatment or prevention of other diseases which involve cell adhesion processes, including, but not limited to, infammation, bone degradation, rheumatoid arthritis, asthma, allergies, adult respiratory distress syndrome, graft versus host disease, organ transplantation, septic shock, psoriasis, eczema, contact dermatitis, osteoporosis, osteoarthritis, atherosclerosis, metastasis, wound healing, diabetic retinopathy, inflammatory bowel disease and other autoimmune diseases.

In summary, the compounds of Formula I of the present invention when tested for their ability to inhibit platelet aggregation (using platelet rich plasma) show an IO₅₀ value (the concentration of antagonist which inhibits platelet aggregation by 50% relative to a control lacking the antagonist) of less than 100 um (uM=micromolar).

Dosage and Formulation

The compounds of the present invention can be administered in such oral dosage forms as tablets, capsules (each of which includes sustained release or timed release formulations), pills, powders, granules, elixirs, tinctures, suspensions, syrups, and emulsions. Likewise, they may also be administered in intravenous (bolus or infusion), intraperitoneal, subcutaneous, or intramuscular form, all using dosage forms well known to those of ordinary skill in the pharmaceutical arts. An effective but non-toxic amount of the compound desired can be employed as an anti-aggregation agent. Finally, the compounds of the invention may also be administered intranasally.

The compounds of this invention can be administered by any means that produces contact of the active agent with the agent's site of action, glycoprotein IIb/IIIa (GPIIb/IIIa), in the body of a mammal. They can be administered by any conventional means available for use in conjunction with pharmaceuticals, either as individual therapeutic agents or in a combination of therapeutic agents, such as a second antiplatelet agent such as aspirin or ticlopidine which are agonist-specific. They can be administered alone, but generally administered with a pharmaceutical carrier selected on the basis of the chosen route of administration and standard pharmaceutical practice.

The dosage regimen for the compounds of the present invention will, of course, vary depending upon known factors, such as the pharmacodynamic characteristics of the particular agent and its mode and route of administration; the species, age, sex, health, medical condition, and weight of the recipient; the nature and extent of the symptoms; the kind of concurrent treatment; the frequency of treatment; the route of administration, the renal and hepatic function of the patient,and the effect desired. An ordinarily skilled physician or veterinarian can readily determine and prescribe the effective amount of the drug required to prevent, counter, or arrest the progress of the condition.

By way of general guidance, the daily oral dosage of each active ingredient, when used for the indicated effects, will range between about 0.001 to 1000 mg/kg of body weight, preferably between about 0.01 to 100 mg/kg of body weight per day, and most preferably between about 0.01 to 20 mg/kg/day. Intravenously, the most preferred doses will range from about 0.001 to about 10 mg/kg/minute during a constant rate infusion. Advantageously, compounds of the present invention may be administered in a single daily dose, or the total daily dosage may be administered in divided doses of two, three, or four times daily.

The compounds for the present invention can be administered in intranasal form via topical use of suitable intranasal vehicles, or via transdermal routes, using those forms of transdermal skin patches wall known to those of ordinary skill in that art. To be administered in the form of a transdermal delivery system, the dosage administration will, of course, be continuous rather than intermittant throughout the dosage regimen.

In the methods of the present invention, the compounds herein described in detail can form the active ingredient, and are typically administered in admixture with suitable pharmaceutical diluents, excipients, or carriers (collectively referred to herein as carrier materials) suitably selected with respect to the intended form of administration, that is, oral tablets, capsules, elixirs, syrups and the like, and consistent with conventional pharmaceutical practices.

For instance, for oral administration in the form of a tablet or capsule, the active drug component can be combined with an oral, non-toxic, pharmaceutically acceptable, inert carrier such as lactose, starch, sucrose, glucose, methyl cellulose, magnesium stearate, dicalcium phosphate, calcium sulfate, mannitol, sorbitol and the like; for oral administration in liquid form, the oral drug components can be combined with any oral, non-toxic, pharmaceutically acceptable inert carrier such as ethanol, glycerol, water, and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents, and coloring agents can also be incorporated into the mixture. Suitable binders include starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth, or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes, and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride, and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthan gum, and the like.

The compounds of the present invention can also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamallar vesicles, and multilamellar vesicles. Liposomes can be formed from a variety of phospholipids, such as cholesterol, stearylamine, or phosphatidylcholines.

Compounds of the present invention may also be coupled with soluble polymers as targetable drug carriers. Such polymers can include polyvinylpyrrolidone, pyran copolymer, polyhydroxypropylmethacrylamide-phenol, polyhydroxyethylaspartamidephenol, or polyethyleneoxide-polylysine substituted with palmitoyl residues. Furthermore, the compounds of the present invention may be coupled to a class of biodegradable polymers useful in achieving controlled release of a drug, for example, polylactic acid, polyglycolic acid, copolymers of polylactic and polyglycolic acid, polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals, polydihydropyrans, polycyanoacylates, and crosslinked or amphipathic block copolymers of hydrogels.

Dosage forms (pharmaceutical compositions) suitable for administration may contain from about 1 milligram to about 100 milligrams of active ingredient per dosage unit. In these pharmaceutical compositions the active ingredient will ordinarily be present in an amount of about 0.5-95% by weight based on the total weight of the composition.

The active ingredient can be administered orally in solid dosage forms, such as capsules, tablets, and powders, or in liquid dosage forms, such as elixirs, syrups, and suspensions. It can also be administered parenterally, in sterile liquid dosage forms.

Gelatin capsules may contain the active ingredient and powdered carriers, such as lactose, starch, cellulose derivatives, magnesium stearate, stearic acid, and the like. Similar diluents can be used to make compressed tablets. Both tablets and capsules can be manufactured as sustained release products to provide for continuous release of medication over a period of hours. Compressed tablets can be sugar coated or film coated to mask any unpleasant taste and protect the tablet from the atmosphere, or enteric coated for selective disintegration in the gastrointestinal tract.

Liquid dosage forms for oral administration can contain coloring and flavoring to increase patient acceptance.

In general, water, a suitable oil, saline, aqueous dextrose (glucose), and related sugar solutions and glycols such as propylene glycol or polyethylene glycols are suitable carriers for parenteral solutions. Solutions for parenteral administration preferably contain a water soluble salt of the active ingredient, suitable stabilizing agents, and if necessary, buffer substances. Antioxidizing agents such as sodium bisulfite, sodium sulfite, or ascorbic acid, either alone or combined, are suitable stabilizing agents. Also used are citric acid and its salts and sodium EDTA. In addition, parenteral solutions can contain preservatives, such as benzalkonium chloride, methyl- or propyl-paraben, and chlorobutanol.

Suitable pharmaceutical carriers are described in Remington's Pharmaceutical Sciences, Mack Publishing Company, a standard reference text in this field.

Representative useful pharmaceutical dosage-forms for administration of the compounds of this invention can be illustrated as follows:

Capsules

A large number of unit capsules are prepared by filling standard two-piece hard gelatin capsules each with 1-20 milligrams of powdered active ingredient, 150 milligrams of lactose, 50 milligrams of cellulose, and 6 milligrams magnesium stearate.

Soft Gelatin Capsules

A mixture of active ingredient in a digestable oil such as soybean oil, cottonseed oil or olive oil is prepared and injected by means of a positive displacement pump into gelatin to form soft gelatin capsules containing 1-20 milligrams of the active ingredient. The capsules are washed and dried.

Tablets

A large number of tablets are prepared by conventional procedures so that the dosage unit was 1-20 milligrams of active ingredient, 0.2 milligrams of colloidal silicon dioxide, 5 milligrams of magnesium stearate, 275 milligrams of microcrystalline cellulose, 11 milligrams of starch and 98.8 milligrams of lactose. Appropriate coatings may be applied to increase palatability or delay absorption.

Injectable

A parenteral composition suitable for administration by injection is prepared by stirring 1.5% by weight of active ingredient in 10% by volume propylene glycol and water. The solution is made isotonic with sodium chloride and sterilized.

Suspension

An aqueous suspension is prepared for oral administration so that each 5 mL contain 1-20 mg of finely divided active ingredient, 200 mg of sodium carboxymethyl cellulose, 5 mg of sodium benzoate, 1.0 g of sorbitol solution, U.S.P., and 0.025 mL of vanillin.

The compounds of the present invention may be administered in combination with a second therapeutic agent selected from: an anti-coagulant agent such as warfarin or heparin; an anti-platelet agent such as aspirin, piroxicam or ticlopidine; a thrombin inhibitor such as a boropeptide thrombin inhibitor, or hirudin; or a thrombolytic agent such as plasminogen activators, such as tissue plasminogen activator, anistreplase, urokinase or streptokinase. The compound of Formula I and such second therapeutic agent can be administered separately or as a physical combination in a single dosage unit, in any dosage form and by various routes of administration, as described above.

The compound of Formula I may be formulated together with the second therapeutic agent in a single dosage unit (that is, combined together in one capsule, tablet, powder, or liquid, etc.). When the compound of Formula I and the second therapeutic agent are not formulated together in a single dosage unit, the compound of Formula I and the second therapeutic agent (anti-coagulant agent, anti-platelet agent, thrombin inhibitor, and/or thrombolytic agent) may be administered essentially at the same time, or in any order; for example the compound of Formula I may be administered first, followed by administration of the second agent (anti-coagulant agent, anti-platelet agent, thrombin inhibitor, and/or thrombolytic agent). When not administered at the same time, preferably the administration of the compound of Formula I and the second therapeutic agent occurs less than about one hour apart.

A preferable route of administration of the compound of Formula I is oral. Although it is preferable that the compound of Formula I and the second therapeutic agent (anti-coagulant agent, anti-platelet agent, thrombin inhibitor, and/or thrombolytic agent) are both administered by the same route (that is, for example, both orally), if desired, they may each be administered by different routes and in different dosage forms (that is, for example, one component of the combination product may be administered orally, and another component may be administered intravenously).

The dosage of the compound of Formula I when administered alone or in combination with a second therapeutic agent may vary depending upon various factors such as the pharmacodynamic characteristics of the particular agent and its mode and route of administration, the age, health and weight of the recipient, the nature and extent of the symptoms, the kind of concurrent treatment, the frequency of treatment, and the effect desired, as described above.

Although the proper dosage of the compound of Formula I when administered in combination with the second therapeutic agent will be readily ascertainable by a medical practitioner skilled in the art, once armed with the present disclosure, by way of general guidance, where the compounds of this invention are combined with anti-coagulant agents, for example, a daily dosage may be about 0.1 to 100 milligrams of the compound of Formula I and about 1 to 7.5 milligrams of the anticoagulant, per kilogram of patient body weight. For a tablet dosage form, the novel compounds of this invention generally may be present in an amount of about 1 to 10 milligrams per dosage unit, and the anti-coagulant in an amount of about 1 to 5 milligrams per dosage unit.

Where the compounds of Formula I are administered in combination with a second anti-platelet agent, by way of general guidance, typically a daily dosage may be about 0.01 to 25 milligrams of the compound of Formula I and about 50 to 150 milligrams of the additional anti-platelet agent, preferably about 0.1 to 1 milligrams of the compound of Formula I and about 1 to 3 milligrams of antiplatelet agents, per kilogram of patient body weight.

Further, by way of general guidance, where the compounds of Formula I are adminstered in combination with thrombolytic agent, typically a daily dosage may be about 0.1 to 1 milligrams of the compound of Formula I, per kilogram of patient body weight and, in the case of the thrombolytic agents, the usual dosage of the thrombolyic agent when administered alone may be reduced by about 70-80% when administered with a compound of Formula I.

Where two or more of the foregoing second therapeutic agents are administered with the compound of Formula I, generally the amount of each component in a typical daily dosage and typical dosage form may be reduced relative to the usual dosage of the agent when administered alone, in view of the additive or synergistic effect of the therapeutic agents when administered in combination.

Particularly when provided as a single dosage unit, the potential exists for a chemical interaction between the combined active ingredients. For this reason, when the compound of Formula I and a second therapeutic agent are combined in a single dosage unit they are formulated such that although the active ingredients are combined in a single dosage unit, the physical contact between the active ingredients is minimized (that is, reduced). For example, one active ingredient may be enteric coated. By enteric coating one of the active ingredients, it is possible not only to minimize the contact between the combined active ingredients, but also, it is possible to control the release of one of these components in the gastrointestinal tract such that one of these components is not released in the stomach but rather is released in the intestines. One of the active ingredients may also be coated with a sustained-release material which effects a sustained-release throughout the gastrointestinal tract and also serves to minimize physical contact between the combined active ingredients. Furthermore, the sustained-released component can be additionally enteric coated such that the release of this component occurs only in the intestine. Still another approach would involve the formulation of a combination product in which the one component is coated with a sustained and/or enteric release polymer, and the other component is also coated with a polymer such as a lowviscosity grade of hydroxypropyl methylcellulose (HPMC) or other appropriate materials as known in the art, in order to further separate the active components. The polymer coating serves to form an additional barrier to interaction with the other component.

These as well as other ways of minimizing contact between the components of combination products of the present invention, whether administered in a single dosage form or administered in separate forms but at the same time by the same manner, will be readily apparent to those skilled in the art, once armed with the present disclosure.

The present invention also includes pharmaceutical kits useful, for example, in the inhibition of platelet aggregation, the treatment of blood clots, and/or the treatment of thromboembolic disorders, which comprise one or more containers containing a pharmaceutical composition comprising a therapeutically effective amount of a compound of Formula I. Such kits may further include, if desired, one or more of various conventional pharmaceutical kit components, such as, for example, containers with one or more pharmaceutically acceptable carriers, additional containers, etc., as will be readily apparent to those skilled in the art. Instructions, either as inserts or as labels, indicating quantities of the components to be administered, guidelines for administration, and/or guidelines for mixing the components, may also be included in the kit.

In the present disclosure it should be understood that the specified materials and conditions are important in practicing the invention but that unspecified materials and conditions are not excluded so long as they do not prevent the benefits of the invention from being realized. 

What is claimed is:
 1. A compound of the formula

or a pharmaceutically acceptable salt thereof, wherein: B is selected from R²HN(R^(2a)N═)C—, R²HN(R^(2a)N═)CNH—; Z¹ and Z² are independently selected from a single bond, C₁-C₆ alkylene, substituted with 0-1 by R^(2b), wherein any carbon atom in the alkylene chain may be replaced with O, with the proviso that O when present is adjacent to saturated or aromatic carbon atoms; V is selected from a single bond, 1,4-phenylene; wherein the phenylene group is substituted from 0-2 R⁵ substituents; provided that B, Z¹, Z² and V are chosen such that the oxime carbon in Formula I is not directly connected to an oxygen or nitrogen atom of B, Z¹ or Z²; L is selected from C₁-C₄ alkylene C₁-C₄ alkylene substituted with C₁-C₄ alkyl; R¹ is selected from H, C₁-C₆ alkyl, C₃-C₇ cycloalkyl, aryl; R² is selected from H, C₁-C₆ alkyl, benzyl; R^(2a) is selected from H, OH C₁-C₆ alkyloxycarbonyl, C₃-C₇ cycloalkyloxycarbonyl, benzyloxycarbonyl, C₁-C₄ alkylcarbonyloxy(C₁-C₂ alkyl)oxycarbonyl, C₃-C₈ cycloalkylcarbonyloxy(C₁-C₂ alkyl)oxycarbonyl; R^(2b) is selected from H, C₁-C₆ alkyl; R³ is selected from H, C₁-C₈ alkyl, substituted with 0-1 R⁶, C₂-C₈ alkenyl, substituted with 0-1 R⁶, C₂-C₈ alkynyl, substituted with 0-1 R⁶, C₃-C₇ cycloalkyl, substituted with 0-1 R⁶, aryl, CONR⁷R⁸; R⁴ is selected from H, NR¹¹R¹⁵; R⁵ is selected from H, halo, C₁-C₄ alkyl, C₁-C₄ haloalkyl, C₁-C₄ alkyloxy; R⁶ is selected from H, C₁-C₆ alkyl, C₂-C₄ alkenyl, C₃-C₇ cycloalkyl, C₁-C₄ perfluoroalkyl, C₁-C₆ alkyloxy, C₁-C₆ alkylcarbonyl, aryl, CONR⁷R⁸ OR¹⁴ NR⁹R¹⁰, NR¹¹COR¹², NR¹¹CO₂R¹³ NR¹¹CONR⁷R⁸, NR¹¹SO₂R¹², SO₂R¹², SO₂NR⁷R⁸, halo; R⁷ and R⁸ are independently selected from H, C₁-C₆ alkyl, C₃-C₇ cycloalkyl, C₄-C₈ cycloalkylalkyl, aryl, aryl(C₁-C₄ alkyl); R⁹ and R¹⁰ are independently selected from H, C₁-C₆ alkyl, C₃-C₇ cycloalkyl, C₄-C₈ cycloalkylalkyl, aryl, aryl(C₁-C₄ alkyl); R¹¹ is selected from H, C₁-C₄ alkyl; R¹² is selected from C₁-C₆ alkyl, C₃-C₇ cycloalkyl, aryl, aryl(C₁-C₄ alkyl); R¹³ is selected from C₁-C₆ alkyl, C₃-C₇ cycloalkyl, C₄-C₈ cycloalkylalkyl, C₁-C₆ haloalkyl, arylmethyl; R¹⁴ is selected from H₁ C₁-C₆ alkyl, C₃-C₇ cycloalkyl, C₄-C₈ cycloalkylalkyl, aryl, aryl (C₁-C₄ alkyl); R¹⁵ is selected from COR¹⁶, CO₂R¹⁷, CONR¹⁸R¹⁹, SO₂R²⁰, SO₂NR¹⁸R¹⁹; R¹⁶ is selected from C₁-C₈ alkyl, substituted with 0-2 R⁶, aryl, aryl(C₁-C₄ alkyl); R¹⁷ is selected from C₁-C₈ alkyl, substituted with 0-2 R⁶, aryl(C₁-C₄ alkyl); R¹⁸ and R¹⁹ are selected from H, C₁-C₈ alkyl, substituted with 0-2 R⁶, aryl, aryl(C₁-C₄ alkyl); R²⁰ is selected from C₁-C₈ alkyl, substituted with 0-2 R⁶, aryl, aryl(C₁-C₄ alkyl); Y is selected from OH, C₁-C₁₀ alkyloxy, C₃-C₇ cycloalkyloxy, C₄-C₈ cycloalkyloxy, arylmethyloxy, C₁-C₆ alkylcarbonyloxy(C₁-C₄ alkyl)oxy, C₁-C₆ alkyloxycarbonyloxy(C₁-C₄ alkyl)oxy, C₃-C₇ cycloalkylcarbonyloxy(C₁-C₄ alkyl)oxy, C₃-C₇ cycloalkyloxycarbonyloxy(C₁-C₄)oxy, aryloxycarbonyloxy(C₁-C₄ alkyl)oxy, arylcarbonyloxy(C₁-C₄ alkyl)oxy, (C₁-C₂ alkyloxy(C₁-C₄)alkyl)carbonyloxy(C₁-C₂ alkyl)oxy, (5-(C₁-C₄ alkyl)-1,3-dioxa-cyclopenten-2-one-4-yl)methyloxy, (5-phenyl-1,3-dioxa-cyclopenten-2-one-4-yl)methyloxy, (R²¹)(R²²)N(C₂-C₄ alkyl)oxy-,(R²¹)(R²²)(R²³)N⁺(C₂-C₄ alkyl)oxy-(X⁻), where X⁻ is a pharmaceutically acceptable anionic group such as halide, sulfate, organosulfonate or organocarboxylate; R²¹ and R²² are selected from C₁-C₄ alkyl, R²³ is selected from C₁-C₄ alkyl, R²⁴ is phenyl or naphthyl substituted with 0-3 substituents selected from C₁-C₆ alkyl, C₁-C₆ alkyloxy, halo, CN, C₁-C₄ haloalkyl, C₁-C₄ haloalkoxy, NO₂, NH₂, C₁-C₆ alkylamino, C₂-C₁₀ dialkylamino, C₁-C₆ alkylcarbonylamino, C₁-C₆ alkylcarbonyl, C₁-C₆ alkyloxycarbonyl, C₁-C₆ alkylthio, C₁-C₆ alkylsulfinyl, C₁-C₆ alkylsulfonyl, C₁-C₆ alkylsulfonylamino, carboxy, aminocarbonyl, C₁-C₆ alkylaminocarbonyl, C₂-C₁₀ dialkylaminocarbonyl or methylenedioxy; R²⁵ is pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, pyrrolyl, pyrazolyl, imidazolyl, triazolyl, tetrazolyl, furanyl, oxazolyl, isoxazolyl, thienyl, thiazolyl, oxadiazolyl, thiadiazolyl, quinolinyl, isoquinolinyl, benzofuranyl, indolyl, indazolyl, benzimidazolyl or benzothiophenyl, substituted with 0-3 groups selected from C₁-C₆ alkyl, C₁-C₆ alkyloxy, CN, NO₂, halo, C₁-C₄ haloalkyl, C₁-C₆ alkylthio, C₁-C₆ alkylsulfinyl, C₁-C₆ alkylsulfonyl, NH₂, C₁-C₆ alkylcarbonylamino, C₁-C₆ alkylamino or C₂-C₁₀ dialkylamino; and wherein aryl is a phenyl or naphthyl group substituted with 0-3 substituents selected from C₁-C₆ alkyl, C₁-C₆ alkyloxy, halo, CN, C₁-C₄ haloalkyl, C₁-C₄ haloalkoxy, NO₂, NH₂, C₁-C₆ alkylamino, C₂-C₁₀ dialkylamino, C₁-C₆ alkylcarbonylamino, C₁-C₆ alkylcarbonyl, C₁-C₆alkyloxycarbonyl, C₁-C₆ alkylthio, C₁-C₆ alkylsulfinyl, C₁-C₆ alkylsulfonyl, 1-C₆ alkylsulfonylamino, carboxy, aminocarbonyl, C₁-C₆ alkylaminocarbonyl, C₂-C₁₀ dialkylaminocarbonyl, methylenedioxy and 0-1 substituent selected from R²⁴CO, R²⁴O, R²⁴NH, R²⁴S, R²⁴SO, R²⁴SO₂, R²⁴NHCO, R²⁴CONH, R²⁴NHSO₂, R²⁴SO₂NH or phenyl substituted with 0-3 substituents chosen from C₁-C₆ alkyl, C₁-C₆ alkyloxy, halo or C₁-C₄ haloalkyl, except that in the case for R²⁰ aryl can be as defined above but where the three substituents on the phenyl and naphthyl groups may in addition include one substituent selected from R²⁵, R²⁵CO, R²⁵O, R²⁵NH, R²⁵S, R²⁵SO, R²⁵SO₂, R²⁵NHCO, R²⁵CONH, R²⁵NHSO₂ or R²⁵SO₂NH.
 2. A compound of claim 1 wherein; Z¹ and Z² are a single bond; V is selected from 1,4-phenylene, wherein the phenylene group is substituted with 0-2 R⁵ substituents; L is a C₁-C₄ alkylene chain; R¹ is selected from H, C₁-C₆ alkyl; R² is H; R^(2a) is selected from H, OH C₁-C₂ alkyloxycarbonyl, C₅-C₇ cycloalkyloxycarbonyl, benzyloxycarbonyl, C₁-C₂ alkylcarbonyloxy(C₁-C₂ alkyl)oxycarbonyl, C₅-C₆ cycloalkylcarbonyloxy(C₁-C₂ alkyl)oxycarbonyl; R³ is selected from H, C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, aryl, aryl(C₁-C₂ alkyl), CONR⁷R⁸; R⁵ is selected from H, halo, methyl, trifluoromethyl, methoxy; R¹¹ is H or methyl; R¹⁵ is selected from CO₂R¹⁷, SO₂R²⁰; R¹⁷ is selected from C₁-C₈ alkyl, substituted with 0-1 R⁶, aryl(C₁-C₄ alkyl); R²⁰ is selected from C₁-C₈ alkyl, substituted with 0-1 R⁶, aryl, aryl(C₁-C₄ alkyl; R²¹ and R²² are selected from C₁-C₂ alkyl; R²³ is selected from C₁-C₂ alkyl; Y is selected from OH, C₁-C₁₀ alkyloxy, benzyloxy, C₁-C₄ alkylcarbonyloxy(C₁-C₂ alkyl)oxy, C₁-C₄ alkyloxycarbonyloxy(C₁-C₂ alkyl)oxy, C₅-C₆ cycloalkylcarbonyloxy(C₁-C₂ alkyl)oxy, C₅-C₆ cycloalkyloxycarbonyloxy(C₁-C₂)oxy, 1-(2-(2-methoxypropyl)carbonyloxy)ethoxy, (5-methyl-1,3-dioxa-cyclopenten-2-one-4-yl)methyloxy, (5-phenyl-1,3-dioxa-cyclopenten-2-one-4-yl)methyloxy, ((R²¹)(R²²)N)ethoxy-, ((R²¹)(R²²)(R²³)N⁺)ethoxy-(X⁻), where X⁻ is a pharmaceutically acceptable anionic group such as halide, sulfate, organosulfonate or organocarboxylate; and wherein aryl is defined as above.
 3. A compound of claim 2 selected from the group consisting of 3-[3-[[(4-amidinophenylmethylene)amino]oxy]-1-oxopropylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]propanoic acid 2-[3-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]propanoic acid 3-[3-[[(4-amidinophenylmethylene)amino]oxy]-1-oxopropylamino]-2-(S)-[n-butyloxycarbonylamino]propanoic acid 2-[3-[[(4-amidinophenylmethylene)amino]oxy]-1-oxoethylamino]-2-(S)-[n-butyloxycarbonylamino]propanoic acid 3-[3-[[(4-amidino-1-phenylethylidene)amino]oxy]-1-oxopropylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]propanoic acid 2-[3-[[(4-amidino-1-phenylethylidene)amino]oxy]-1-oxoethylamino]-2-(S)-[(3-methylphenyl)sulfonylamino]propanoic acid 3-[3-[[(4-amidino-1-phenylethylidene)amino]oxy]-1-oxopropylamino]-2-(S)-[n-butyloxycarbonylamino]propanoic acid 2-[3-[[(4-amidino-1-phenylethylidene)amino]oxy]-1-oxoethylamino]-2-(S)-[n-butyloxycarbonylamino]propanoic acid.
 4. A prodrug ester of a compound of claim 3 wherein the ester moiety is selected from the group consisting of: methyl, ethyl, i-propyl, n-butyl, i-butyl, benzyl, methylcarbonyloxymethyl, ethylcarbonyloxymethyl, t-butylcarbonyloxymethyl, cyclohexylcarbonyloxymethyl, cyclohexyloxycarbonyloxymethyl, t-butyloxycarbonyloxymethyl, dimethylaminoethyl, diethylaminoethyl, pyrrolidinylethyl, morpholinylethyl, trimethylammoniumethyl (X⁻).
 5. A nitrogen-derivatized prodrug form of a compound of claim 3 wherein the prodrug moiety is selected from the group consisting of: OH, methoxycarbonyl, ethoxycarbonyl, cyclohexylcarbonyl, benzyloxycarbonyl, methylcarbonyloxymethylcarbonyl, ethylcarbonyloxylmethylcarbonyl, cyclohexylcarbonyloxymethylcarbonyl.
 6. An ester of a nitrogen-derivatized prodrug form of a compound of claim 3, wherein the ester moiety is selected from the group consisting of: methyl, ethyl, i-propyl, n-butyl, i-butyl, benzyl, methylcarbonyloxymethyl, ethylcarbonyloxymethyl, t-butylcarbonyloxymethyl, cyclohexylcarbonyloxymethyl, cyclohexyloxycarbonyloxymethyl, t-butyloxycarbonyloxymethyl, dimethylaminoethyl, diethylaminoethyl, pyrrolidinylethyl, morpholinylethyl, trimethylammoniumethyl (X⁻).
 7. A pharmaceutical composition comprising a pharmaceutical carrier and a therapeutically effective amount of a compound of claim 1 or a pharmaceutically acceptable salt form thereof.
 8. A pharmaceutical composition comprising a pharmaceutical carrier and a therapeutically effective amount of a compound of claim 2 or a pharmaceutically acceptable salt form thereof.
 9. A pharmaceutical composition comprising a pharmaceutical carrier and a therapeutically effective amount of a compound of claim 3 or a pharmaceutically acceptable salt form thereof.
 10. A method of inhibiting the aggregation of blood platelets which comprises administering to a host in need of such inhibition a therapeutically effective amount of a compound of claim
 1. 11. A method of inhibiting the aggregation of blood platelets which comprises administering to a host in need of such inhibition a therapeutically effective amount of a compound of claim
 2. 12. A method of inhibiting the aggregation of blood platelets which comprises administering to a host in need of such inhibition a therapeutically effective amount of a compound of claim
 3. 